add missing use statement

Author: xabbuh

Tests/Controller/AbstractControllerTest.php

@@ -11,6 +11,7 @@
 
 namespace Symfony\Bundle\FrameworkBundle\Tests\Controller;
 
+use Doctrine\Persistence\ManagerRegistry;
 use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
 use Symfony\Bundle\FrameworkBundle\Tests\TestCase;
 use Symfony\Component\DependencyInjection\Container;