title: Event Listener not registered or called on Doctrine Event
body: <p>I have followed the instructions in the cookboock : <a href="http://symfony.com/doc/current/cookbook/doctrine/event_listeners_subscribers.html" rel="noreferrer">http://symfony.com/doc/current/cookbook/doctrine/event_listeners_subscribers.html</a>
  but unfortunately my EventListener does not get called.</p>
  
  <p>service.yml</p>
  
  <pre><code>services:
        strego.acl.eventlistener:
          class: Strego\TippBundle\EventListener\AclUpdater
          tags:
              - { name: doctrine.event_listener, event: prePersist, connection: default }
  </code></pre>
  
  <p>And here is my Eventlistener to execute:</p>
  
  <pre><code>namespace Strego\TippBundle\EventListener;
  use Doctrine\ORM\Event\LifecycleEventArgs;
  use Symfony\Component\DependencyInjection\ContainerAwareInterface;
  use Symfony\Component\DependencyInjection\ContainerInterface;
  
  class AclUpdater implements ContainerAwareInterface
  {
  
      protected $container;
  
  
      public function prePersist(LifecycleEventArgs $args) {
          $args-&gt;idonotexist(); // should crash if called
          }
      }
  
      public function setContainer(ContainerInterface $container = null) {
          $this-&gt;container = $container;
      }
  }
  </code></pre>
  
  <p>and now my controller code, with which i want to test it:</p>
  
  <pre><code>public function testAction($id){
          $em = $this-&gt;getDoctrine()-&gt;getEntityManager();
          $entity = $em-&gt;getRepository('StregoTippBundle:BetGroup')-&gt;find($id);
          $entity-&gt;setUpdatedAt(new \DateTime());
          $entity-&gt;setTitle('update Name! #2');
          $em-&gt;persist($entity);
          $em-&gt;flush();         
          return new \Symfony\Component\HttpFoundation\Response("done");
      }
  </code></pre>
  
  <p>I have no Idae why my prePersist Action is not called. Does anyone see the issue with my code?</p>