stop interpreting null json as string

src/Utils/Controller/LuRoute.php

             try
             {
                 $json = json_decode($value, true);
-                if (is_null($json)) {
-                    $json = $value . "";
-                }
                 $typedValue = call_user_func_array(array($class->getName(), "jsonDeserialize"), array($json));
             }
             catch (LuDboDeserializeException $e)