Opt ssl read log

[chenBright]

What problem does this PR solve?

Issue Number: #977

Problem Summary:

对端发送完数据后关闭连接或者shutdown ssl，就有可能出现ssl_error=SSL_ERROR_SYSCALL/SSL_ERROR_ZERO_RETURN、nr>0、e=0，这应该是正常情况，没有必要打印WARNING日志。

What is changed and the side effects?

Changed:

Side effects:

• Performance effects(性能影响):

• Breaking backward compatibility(向后兼容性):

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Check List:

• Please make sure your changes are compilable(请确保你的更改可以通过编译).
• When providing us with a new feature, it is best to add related tests(如果你向我们增加一个新的功能, 请添加相关测试).
• Please follow Contributor Covenant Code of Conduct.(请遵循贡献者准则).

[Huixxi]

SSL_ERROR_SYSCALL 这个也要忽略么？

[chenBright]

SSL_get_error文档中提到，这个场景只是读到EOF而已，不算是错误。

SSL_ERROR_SYSCALL
Some I/O error occurred. The OpenSSL error queue may contain more information on the error. If the error queue is empty (i.e. ERR_get_error() returns 0), ret can be used to find out more about the error: If ret == 0, an EOF was observed that violates the protocol. If ret == -1, the underlying BIO reported an I/O error (for socket I/O on Unix systems, consult errno for details).

[Huixxi]

SSL_get_error文档中提到，这个场景只是读到EOF而已，不算是错误。

SSL_ERROR_SYSCALL
Some I/O error occurred. The OpenSSL error queue may contain more information on the error. If the error queue is empty (i.e. ERR_get_error() returns 0), ret can be used to find out more about the error: If ret == 0, an EOF was observed that violates the protocol. If ret == -1, the underlying BIO reported an I/O error (for socket I/O on Unix systems, consult errno for details).

EOF只是ret==0的时候吧，ret==-1的时候该怎么判断呢？

[chenBright]

加个判断吧，(ssl_error != SSL_ERROR_ZERO_RETURN && ssl_error != SSL_ERROR_SYSCALL) || nr < 0 || BIO_fd_non_fatal_error(errno) == 0，这样就能只过滤eof的日志了。

[wwbmmm]

LGTM