message: fix init rshutdown_functions
diff: @@ -577,6 +577,7 @@ static void php_swoole_init_globals(zend_swoole_globals *swoole_globals)
  swoole_globals->use_namespace = 1;
  swoole_globals->use_shortname = 1;
  swoole_globals->fast_serialize = 0;
  + swoole_globals->rshutdown_functions = NULL;
  }
  int php_swoole_length_func(swProtocol *protocol, swConnection *conn, char *data, uint32_t length)
  