title: Symfony 3.1 EventListener method executed two times?
body: <p>Hello I made a EventListener to do things before send a response to the request.
  So this is my EventListener:</p>
  
  <pre><code>namespace AppBundle\EventListener;
  
  use Symfony\Component\HttpKernel\Event\FilterControllerEvent;
  use Symfony\Component\HttpFoundation\Session\Session;
  use Doctrine\ORM\EntityManager;
  
  class RequestListener {
  
      private $em;
      private $session;
  
      public function __construct(EntityManager $em, Session $session) {
          $this-&gt;em = $em;
          $this-&gt;session = $session;
      }
  
      public function onKernelController(FilterControllerEvent $event) {
          $repo=$this-&gt;em-&gt;getRepository("AppBundle:FlashMessage");
          $repo-&gt;addFlashMessage("test","content");
      }
  
  }
  </code></pre>
  
  <p>And add it to my services:</p>
  
  <pre><code>&lt;/services&gt;
      &lt;service id="app.request.listener" class="AppBundle\EventListener\RequestListener"&gt;
          &lt;argument type="service" id="doctrine.orm.entity_manager"/&gt;
          &lt;argument type="service" id="session" /&gt; 
          &lt;tag name="kernel.event_listener" event="kernel.controller" /&gt;
      &lt;/service&gt;
  &lt;/services&gt;
  </code></pre>
  
  <p>Every things work fine. But too fine ! In fact, on each request from my web browser, two entries are made in my database table (the method onKernelController seem to be executed two times on each request). So why two entry is created on each request ?</p>
  
  <p>Edit : php bin/console debug:event-dispatcher| grep -i AppBundle
  give me:</p>
  
  <pre><code>  #1      AppBundle\EventListener\RequestListener::onKernelController()          0   
  </code></pre>