Symfony + Ratchet loosing EntityManager Object in OnMessage function
Hi, i have a problem with objects in OnMessage function.

```php
$entity = $this->getUserQuestionById($data->UserQuestionId);

protected function getUserQuestionById($id)
   {
        $em = $this->container->get('doctrine')->getEntityManager();
        if ($em->getConnection()->ping() === false) {
            $em->getConnection()->close();
            $em->getConnection()->connect();
        }
        $entity = $em->getRepository('XXXBundle:XxxxXxxx')->find($id);
        return $entity ? $entity : false;
    }
```
i passed ContainerInterface to the constructor 

after about 1 week ratchet cant see my entity manager.
where I made a mistake?