Add missing use statement

Author: Totof6942

routing/redirect_trailing_slash.rst

@@ -42,6 +42,7 @@ system, as explained below:
         // src/AppBundle/Controller/RedirectingController.php
         namespace AppBundle\Controller;
 
+        use Sensio\Bundle\FrameworkExtraBundle\Configuration\Route;
         use Symfony\Bundle\FrameworkBundle\Controller\Controller;
         use Symfony\Component\HttpFoundation\Request;