Fix the documentation from review

Author: Simperfit

routing/redirect_in_config.rst

@@ -148,7 +148,7 @@ action:
             '_controller' => 'Symfony\Bundle\FrameworkBundle\Controller\RedirectController::redirectAction',
             'route'       => 'sonata_admin_dashboard',
             'permanent'   => true,
-            'keepQueryParams' => true
+            'keepQueryParams' => true,
         )));
 
         return $collection;