Connection closed immediately
Hi, 
First, Thanks for your amazing job. Really helpfull ! 
I have an issue with a device pre configured to connect to the websocket server.  The connection is closed immediately after it s opened. The device is trying to reconnect all the time.
```
 public function onOpen(ConnectionInterface $conn)
    {
      echo "on open\r\n";
      $this->repository->addClient($conn);
    }

    public function onClose(ConnectionInterface $conn)
    {
      echo "on close \r\n";
      $this->repository->removeClient($conn);
    }
```

my logs are : 
on open
on close
on open
on close
on open
on close

I had an other web socket server and the connection worked fine. Maybe i missed something with your websocket server.
Do you have an idea ? 