modify format

common/models/forms/OrderForm.php

@@ -581,7 +581,7 @@ class OrderForm extends Model
         $hash = '';
         $max = strlen($seed) - 1;
         for ($i = 0; $i < $length; $i++) {
-            $hash .= $seed{mt_rand(0, $max)};
+            $hash .= $seed[mt_rand(0, $max)];
         }
         return $hash;
     }