Improve Server methods' return value.
Improve Server methods' return value.

swoole/swoole-src,LinkedDestiny/swoole-src,swoole/swoole-src,swoole/swoole-src,swoole/swoole-src,LinkedDestiny/swoole-src,swoole/swoole-src,swoole/swoole-src,swoole/swoole-src,LinkedDestiny/swoole-src,LinkedDestiny/swoole-src,LinkedDestiny/swoole-src,LinkedDestiny/swoole-src,LinkedDestiny/swoole-src