avoid extra redirect; correctly show auth.net errors on failed transaction

CRM/Core/Payment/MJWTrait.php

@@ -280,7 +280,7 @@ trait CRM_Core_Payment_MJWTrait {
     else {
       $qfKey = $params->getCustomProperty('qfKey');
       $parsedUrl = parse_url($params->getCustomProperty('entryURL'));
-      $urlPath = substr($parsedUrl['path'], 1);
+      $urlPath = trim($parsedUrl['path'], '/');
       $query = $parsedUrl['query'];
       if (strpos($query, '_qf_Main_display=1') === FALSE) {
         $query .= '&_qf_Main_display=1';