Add protection against concurrent Readers

During my use of the library(server and client both v1.8.7), the server occasionally receives the following prompt,

```
failed to get reader: received header with unexpected rsv bits set: false:true:true
```

which seems to be related to this part of the code.

**write.go** L300:

```
c.writeHeader.rsv1 = false
if flate && (opcode == opText || opcode == opBinary) {
c.writeHeader.rsv1 = true
}
```

Could you please confirm if it is necessary to add the following code here?

```
c.writeHeader.rsv1 = false
c.writeHeader.rsv2 = false
c.writeHeader.rsv3 = false
```

从 write.go 第 300 行附近开始，跟踪并发读取器或写入器处于活动状态时 writeHeader.rsv1、rsv2 和 rsv3 是如何设置的。使用报告的 unexpected RSV-bits error 作为失败信号。当并发读取器场景不再产生无效的 RSV bits，并且在 repository 具有适当的测试入口点时有覆盖该行为的回归测试，即可视为完成。

由索引模型根据 Issue 内容生成。