run bench happen panic

**What is the issue you are having?**

run bench happen panic
```
go test -bench=. -benchmem -benchtime=4s ./... -timeout 30m
```

**Minimal, Complete, and Verifiable Example**
```
E:\code\github\bigcache>go test -bench=. -benchmem -benchtime=4s ./... -timeout 30m
2021/07/28 00:33:28 Allocated new queue in 0s; Capacity: 256044
2021/07/28 00:33:28 Allocated new queue in 0s; Capacity: 512088
2021/07/28 00:33:28 Allocated new queue in 0s; Capacity: 1024176
2021/07/28 00:33:28 Allocated new queue in 0s; Capacity: 88
2021/07/28 00:33:28 Allocated new queue in 0s; Capacity: 585000
2021/07/28 00:33:28 Allocated new queue in 0s; Capacity: 1170000
goos: windows
goarch: amd64
pkg: github.com/allegro/bigcache/v3
cpu: Intel(R) Core(TM) i7-6700 CPU @ 3.40GHz
BenchmarkWriteToCacheWith1Shard-8 7065433 975.0 ns/op 618 B/op 2 allocs/op
BenchmarkWriteToLimitedCacheWithSmallInitSizeAnd1Shard-8 10922888 434.0 ns/op 40 B/op 3 allocs/op
BenchmarkWriteToUnlimitedCacheWithSmallInitSizeAnd1Shard-8 4877270 3916 ns/op 2832 B/op 2 allocs/op
BenchmarkWriteToCache/1-shards-8 5296270 1024 ns/op 595 B/op 3 allocs/op
BenchmarkWriteToCache/512-shards-8 21498430 1795 ns/op 595 B/op 3 allocs/op
BenchmarkWriteToCache/1024-shards-8 1000000 4101 ns/op 619 B/op 3 allocs/op
BenchmarkWriteToCache/8192-shards-8 19716784 1304 ns/op 603 B/op 3 allocs/op
BenchmarkAppendToCache/1-shards-8 253966 20777 ns/op 14109 B/op 2 allocs/op
BenchmarkAppendToCache/512-shards-8 857107 34833 ns/op 14133 B/op 3 allocs/op
BenchmarkAppendToCache/1024-shards-8 211172 22244 ns/op 15587 B/op 3 allocs/op
BenchmarkAppendToCache/8192-shards-8 430000 23187 ns/op 19209 B/op 3 allocs/op
BenchmarkReadFromCache/1-shards-8 panic: runtime error: slice bounds out of range [16:0]

goroutine 654 [running]:
github.com/allegro/bigcache/v3.readKeyFromEntry(...)
E:/code/github/bigcache/encoding.go:62
github.com/allegro/bigcache/v3.(*cacheShard).get(0xc02cc727e0, 0xc0b6fbe4c0, 0x8, 0xa9902f30c0173fa6, 0x0, 0x0, 0x0, 0xc0b6fbe4c0, 0x8)
E:/code/github/bigcache/shard.go:69 +0x617
github.com/allegro/bigcache/v3.(*BigCache).Get(0xc0000201a0, 0xc0b6fbe4c0, 0x8, 0x8, 0x0, 0x0, 0xe81948, 0xc0000443f0)
E:/code/github/bigcache/bigcache.go:119 +0x92
github.com/allegro/bigcache/v3.readFromCache.func1(0xc0b6fbc000)
E:/code/github/bigcache/bigcache_bench_test.go:187 +0x14a
testing.(*B).RunParallel.func1(0xc0b71ca5e0, 0xc0b71ca5d8, 0xc0b71ca5d0, 0xc0a9026240, 0xc0006e2180)
C:/Program Files/Go/src/testing/benchmark.go:779 +0xa5
created by testing.(*B).RunParallel
C:/Program Files/Go/src/testing/benchmark.go:772 +0x19e
panic: runtime error: slice bounds out of range [16:0]

goroutine 653 [running]:
github.com/allegro/bigcache/v3.readKeyFromEntry(...)
E:/code/github/bigcache/encoding.go:62
github.com/allegro/bigcache/v3.(*cacheShard).get(0xc02cc727e0, 0xc0b7132600, 0x8, 0x5de30a872469a8a8, 0x0, 0x0, 0x0, 0xc0b7132600, 0x8)
E:/code/github/bigcache/shard.go:69 +0x617
github.com/allegro/bigcache/v3.(*BigCache).Get(0xc0000201a0, 0xc0b7132600, 0x8, 0x8, 0x0, 0x0, 0xe81948, 0xc0000443f0)
E:/code/github/bigcache/bigcache.go:119 +0x92
github.com/allegro/bigcache/v3.readFromCache.func1(0xc0b7130000)
E:/code/github/bigcache/bigcache_bench_test.go:187 +0x14a
testing.(*B).RunParallel.func1(0xc0b71ca5e0, 0xc0b71ca5d8, 0xc0b71ca5d0, 0xc0a9026240, 0xc0006e2180)
C:/Program Files/Go/src/testing/benchmark.go:779 +0xa5
created by testing.(*B).RunParallel
C:/Program Files/Go/src/testing/benchmark.go:772 +0x19e
panic: runtime error: slice bounds out of range [16:0]

goroutine 651 [running]:
github.com/allegro/bigcache/v3.readKeyFromEntry(...)
E:/code/github/bigcache/encoding.go:62
github.com/allegro/bigcache/v3.(*cacheShard).get(0xc02cc727e0, 0xc0b7044ac0, 0x8, 0x6184bb604bb7176f, 0x0, 0x0, 0x0, 0xc0b7044ac0, 0x8)
E:/code/github/bigcache/shard.go:69 +0x617
github.com/allegro/bigcache/v3.(*BigCache).Get(0xc0000201a0, 0xc0b7044ac0, 0x8, 0x8, 0x100, 0x100, 0x0, 0x0)
E:/code/github/bigcache/bigcache.go:119 +0x92
github.com/allegro/bigcache/v3.readFromCache.func1(0xc0b7042000)
E:/code/github/bigcache/bigcache_bench_test.go:187 +0x14a
testing.(*B).RunParallel.func1(0xc0b71ca5e0, 0xc0b71ca5d8, 0xc0b71ca5d0, 0xc0a9026240, 0xc0006e2180)
C:/Program Files/Go/src/testing/benchmark.go:779 +0xa5
created by testing.(*B).RunParallel
C:/Program Files/Go/src/testing/benchmark.go:772 +0x19e
panic: runtime error: slice bounds out of range [16:0]

goroutine 655 [running]:
github.com/allegro/bigcache/v3.readKeyFromEntry(...)
E:/code/github/bigcache/encoding.go:62
github.com/allegro/bigcache/v3.(*cacheShard).get(0xc02cc727e0, 0xc0b70be0c8, 0x8, 0x5eaad9c5baa7297, 0x0, 0x0, 0x0, 0xc0b70be0c8, 0x8)
E:/code/github/bigcache/shard.go:69 +0x617
github.com/allegro/bigcache/v3.(*BigCache).Get(0xc0000201a0, 0xc0b70be0c8, 0x8, 0x8, 0x0, 0x0, 0xe81948, 0xc0000443f0)
E:/code/github/bigcache/bigcache.go:119 +0x92
github.com/allegro/bigcache/v3.readFromCache.func1(0xc0b70bc000)
E:/code/github/bigcache/bigcache_bench_test.go:187 +0x14a
testing.(*B).RunParallel.func1(0xc0b71ca5e0, 0xc0b71ca5d8, 0xc0b71ca5d0, 0xc0a9026240, 0xc0006e2180)
C:/Program Files/Go/src/testing/benchmark.go:779 +0xa5
created by testing.(*B).RunParallel
C:/Program Files/Go/src/testing/benchmark.go:772 +0x19e
panic: runtime error: slice bounds out of range [16:0]

goroutine 652 [running]:
github.com/allegro/bigcache/v3.readKeyFromEntry(...)
E:/code/github/bigcache/encoding.go:62
github.com/allegro/bigcache/v3.(*cacheShard).get(0xc02cc727e0, 0xc0b6eee900, 0x8, 0x8935f021031cfad9, 0x0, 0x0, 0x0, 0xc0b6eee900, 0x8)
E:/code/github/bigcache/shard.go:69 +0x617
github.com/allegro/bigcache/v3.(*BigCache).Get(0xc0000201a0, 0xc0b6eee900, 0x8, 0x8, 0x100, 0x100, 0x0, 0x0)
E:/code/github/bigcache/bigcache.go:119 +0x92
github.com/allegro/bigcache/v3.readFromCache.func1(0xc000046440)
E:/code/github/bigcache/bigcache_bench_test.go:187 +0x14a
testing.(*B).RunParallel.func1(0xc0b71ca5e0, 0xc0b71ca5d8, 0xc0b71ca5d0, 0xc0a9026240, 0xc0006e2180)
C:/Program Files/Go/src/testing/benchmark.go:779 +0xa5
created by testing.(*B).RunParallel
C:/Program Files/Go/src/testing/benchmark.go:772 +0x19e
panic: runtime error: slice bounds out of range [16:0]

goroutine 650 [running]:
github.com/allegro/bigcache/v3.readKeyFromEntry(...)
E:/code/github/bigcache/encoding.go:62
github.com/allegro/bigcache/v3.(*cacheShard).get(0xc02cc727e0, 0xc0b6f5e740, 0x8, 0xc15c4a05184e2e9c, 0x0, 0x0, 0x0, 0xc0b6f5e740, 0x8)
E:/code/github/bigcache/shard.go:69 +0x617
github.com/allegro/bigcache/v3.(*BigCache).Get(0xc0000201a0, 0xc0b6f5e740, 0x8, 0x8, 0x0, 0x0, 0xe81948, 0xc0000443f0)
E:/code/github/bigcache/bigcache.go:119 +0x92
github.com/allegro/bigcache/v3.readFromCache.func1(0xc03ad58000)
E:/code/github/bigcache/bigcache_bench_test.go:187 +0x14a
testing.(*B).RunParallel.func1(0xc0b71ca5e0, 0xc0b71ca5d8, 0xc0b71ca5d0, 0xc0a9026240, 0xc0006e2180)
C:/Program Files/Go/src/testing/benchmark.go:779 +0xa5
created by testing.(*B).RunParallel
C:/Program Files/Go/src/testing/benchmark.go:772 +0x19e
panic: runtime error: slice bounds out of range [16:0]

goroutine 656 [running]:
github.com/allegro/bigcache/v3.readKeyFromEntry(...)
E:/code/github/bigcache/encoding.go:62
github.com/allegro/bigcache/v3.(*cacheShard).get(0xc02cc727e0, 0xc0b71cb2b8, 0x8, 0xe04c9623b5dbb2bb, 0x0, 0x0, 0x0, 0xc0b71cb2b8, 0x8)
E:/code/github/bigcache/shard.go:69 +0x617
github.com/allegro/bigcache/v3.(*BigCache).Get(0xc0000201a0, 0xc0b71cb2b8, 0x8, 0x8, 0x100, 0x100, 0x0, 0x0)
E:/code/github/bigcache/bigcache.go:119 +0x92
github.com/allegro/bigcache/v3.readFromCache.func1(0xc0006e21a0)
E:/code/github/bigcache/bigcache_bench_test.go:187 +0x14a
testing.(*B).RunParallel.func1(0xc0b71ca5e0, 0xc0b71ca5d8, 0xc0b71ca5d0, 0xc0a9026240, 0xc0006e2180)
C:/Program Files/Go/src/testing/benchmark.go:779 +0xa5
created by testing.(*B).RunParallel
C:/Program Files/Go/src/testing/benchmark.go:772 +0x19e
exit status 2
FAIL github.com/allegro/bigcache/v3 227.442s
2021/07/28 00:37:24 Allocated new queue in 0s; Capacity: 18
2021/07/28 00:37:24 Allocated new queue in 0s; Capacity: 18
PASS
ok github.com/allegro/bigcache/v3/queue 6.892s
2021/07/28 00:37:30 Entry not found
2021/07/28 00:37:31 stored "testkey" in cache.
2021/07/28 00:37:31 empty request.
2021/07/28 00:37:31 test read error
2021/07/28 00:37:31 empty request.
2021/07/28 00:37:31 not found.
2021/07/28 00:37:31 Entry not found
2021/07/28 00:37:31 stored "putKey" in cache.
2021/07/28 00:37:31 invalidDeleteKey not found.
2021/07/28 00:37:31 entry is bigger than max shard size
PASS
ok github.com/allegro/bigcache/v3/server 4.894s
FAIL

```