fix(dashboard): fixed issue triggering refresh after leaving fullscreen/edit…

fix(dashboard): fixed issue triggering refresh after leaving fullscreen/edit mode with time range change

public/app/features/dashboard/dashboard_ctrl.ts

@@ -71,7 +71,6 @@ export class DashboardCtrl {
       };
 
       $scope.broadcastRefresh = function() {
-        $rootScope.performance.panelsRendered = 0;
         $rootScope.$broadcast('refresh');
       };