MAGETWO-51834: Maestro credit cards doesn't pass validation on server side

Author: oshmyheliuk

app/code/Magento/Payment/Model/Method/Cc.php

@@ -145,7 +145,7 @@ public function validate()
                     '|9[0-1][0-9]{11}|92[0-5][0-9]{10})|[4-6][0-9]{13}|8[2-8][0-9]{12})|6(4[4-9][0-9]{13}' .
                     '|5[0-9]{14}))$/',
                     'MI' => '/^(5(0|[6-9])|63|67(?!59|6770|6774))\d*$/',
-                    'MD' => '/^6759(?!24|38|40|6[3-9]|70|76)|676770|676774\d*$/',
+                    'MD' => '/^(6759(?!24|38|40|6[3-9]|70|76)|676770|676774)\d*$/',
                 ];
 
                 $ccNumAndTypeMatches = isset(