fix callback is_url error

helper/refill/RefillFactory.php

@@ -428,7 +428,7 @@ class RefillFactory
             return (substr($haystack, 0, $length) === $needle);
         };
 
-        return $checker("http://",$url) || $checker("https://",$url);
+        return $checker($url,"http://") || $checker($url,"https://");
     }
 
     public function notify_merchant($order_id)