message: Fix useless warning
diff: @@ -17,8 +17,8 @@ $pm->parentFunc = function ($pid) use ($pm) {
  if (!$client->connect('127.0.0.1', $pm->getFreePort())) {
  exit("connect failed\n");
  }
  - $client->send("hello world");
  - Assert::assert($client->recv() == "");
  + @$client->send("hello world");
  + Assert::assert(@$client->recv() == "");
  $pm->kill();
  };
  