externelize group training registration canel limit minutes into params.php

common/manager/EventRegistrationManager.php

@@ -2,6 +2,7 @@
 
 namespace common\manager;
 
+use common\components\Helper;
 use common\models\Card;
 use common\models\CardEventRegistrationForm;
 use common\models\Customer;
@@ -246,7 +247,7 @@ class EventRegistrationManager extends BaseObject
 
         if ($reason != EventRegistration::CANCEL_REASON_CUSTOMER) {
             $timeUntilEventStart = $event->start - $now;
-            if ($timeUntilEventStart < 30 * 60) {
+            if ($timeUntilEventStart < Helper::getGroupTrainingRegistrationCancelLimitMinutes() * 60) {
                 throw new BadRequestHttpException('The reservation is already deleted', self::CANCEL_TIME_LIMIT_REACHED);
             }
         }