Add missing use statement

CRM/Core/Payment/MJWTrait.php

@@ -3,6 +3,7 @@
  * https://civicrm.org/licensing
  */
 
+use CRM_Mjwshared_ExtensionUtil as E;
 /**
  * Shared payment functions that should one day be migrated to CiviCRM core
  * Trait CRM_Core_Payment_MJWTrait