Optimize namespace of http2_client (#3718)
Optimize namespace of http2_client (#3718)

* Optimize namespace of http2_client

* Optimize namespace of http2_client [2]
swoole/swoole-src,swoole/swoole-src,swoole/swoole-src,swoole/swoole-src,swoole/swoole-src,swoole/swoole-src,swoole/swoole-src