资源放在阿里云中，当range请求的响应返回的状态码是200，依旧添加if-match的header，会导致412

第一次请求的响应：
HTTP/1.1 200 OK
Server: openresty/1.13.6.1
Date: Wed, 23 May 2018 08:18:26 GMT
Content-Type: text/plain; charset=utf8
Last-Modified: Thu, 10 May 2018 12:30:58 GMT
Transfer-Encoding: chunked
Connection: keep-alive
cached: HIT
ETag: W/"5af43b82-56f"
Content-Encoding: gzip

第二次请求的头部：
If-Match: W/"5af43b82-56f"
Range: bytes=0-
User-Agent: FileDownloader/1.7.4
Host: 192.168.3.176
Connection: Keep-Alive

请求响应：
HTTP/1.1 412 Precondition Failed
Server: openresty/1.13.6.1
Date: Wed, 23 May 2018 08:18:26 GMT
Content-Type: text/html; charset=utf8
Content-Length: 195
Connection: keep-alive

<title>412 Precondition Failed</title>

412 Precondition Failed

---

openresty/1.13.6.1