Change code for help videos

Change code for in help.controller.js as it was.

src/Umbraco.Web.UI.Client/src/views/common/dialogs/help.controller.js

@@ -36,10 +36,6 @@ angular.module("umbraco")
 
     	    helpService.findVideos(rq).then(function(videos){
     	        $scope.videos = videos;
-
-    	        angular.forEach($scope.videos, function (obj) {
-    	            obj.thumbnail = obj.thumbnail.replace(/(\.[\w\d_-]+)$/i, '_thumb$1');
-    	        });
     	    });
 
         });