message: fix onBufferFull/onBufferEmpty bugs.
diff: @@ -1230,11 +1230,11 @@ static PHP_METHOD(swoole_client, connect)
  cli->onError = client_onError;
  cli->onReceive = client_onReceive;
  cli->reactor_fdtype = PHP_SWOOLE_FD_STREAM_CLIENT;
  - if (!cb->onBufferFull)
  + if (cb->onBufferFull)
  {
  cli->onBufferFull = client_onBufferFull;
  }
  - if (!cb->onBufferEmpty)
  + if (cb->onBufferEmpty)
  {
  cli->onBufferEmpty = client_onBufferEmpty;
  }
  