Use null controller as fake route to be dumpable

src/Silex/Provider/SecurityServiceProvider.php

@@ -550,7 +550,7 @@ class SecurityServiceProvider implements ServiceProviderInterface
         foreach ($this->fakeRoutes as $route) {
             list($method, $pattern, $name) = $route;
 
-            $app->$method($pattern, function() {})->bind($name);
+            $app->$method($pattern, null)->bind($name);
         }
     }