message: fix invalid error message.
diff: @@ -932,7 +932,7 @@ PHP_RSHUTDOWN_FUNCTION(swoole)
  swWorker_clean();
  }
  - if (SwooleGS->start > 0 && SwooleG.running > 0)
  + if (SwooleGS->start > 0 && SwooleG.serv && SwooleG.running > 0)
  {
  if (PG(last_error_message))
  {
  