Remove unsaved dialog when removing a dashboard #7591 (#7733)

public/app/features/dashboard/dashnav/dashnav.ts

@@ -106,6 +106,7 @@ export class DashNavCtrl {
         confirmText: confirmText,
         yesText: 'Delete',
         onConfirm: function() {
+          $scope.dashboardMeta.canSave = false;
           $scope.deleteDashboardConfirmed();
         }
       });