set abstractmessage constant to corrent success value

Classes/Controller/FeElectionController.php

@@ -156,7 +156,7 @@ class FeElectionController extends ActionController
         $this->addFlashMessage(
             LocalizationUtility::translate('controller.fe.election.vote.thank_you', 'election'),
             LocalizationUtility::translate('controller.fe.election.vote.success', 'election'),
-            AbstractMessage::SUCCESS
+            AbstractMessage::OK
         );
         $this->redirect(FeDashboardController::ACTION_INDEX, FeDashboardController::CONTROLLER_NAME);
     }