message: fix shutdown bug
diff: @@ -1231,7 +1231,7 @@ int swReactorThread_dispatch(swProtocol *proto, swSocket *_socket, char *data, u
  void swReactorThread_join(swServer *serv)
  {
  - if (!serv->single_thread)
  + if (serv->single_thread)
  {
  return;
  }
  