[gnome-shell] calendar: chain up to parent on _onDestroy

[Florian Müllner <fmuellner src gnome org>]

commit 5bca4a884e8f02441a89d7b44490339d869e5966
Author: Florian Müllner <fmuellner gnome org>
Date:   Mon Jul 9 13:31:26 2018 +0200

    calendar: chain up to parent on _onDestroy

 js/ui/calendar.js | 2 ++
 1 file changed, 2 insertions(+)
---
diff --git a/js/ui/calendar.js b/js/ui/calendar.js
index 990cac243..815c9f9c9 100644
--- a/js/ui/calendar.js
+++ b/js/ui/calendar.js
@@ -803,6 +803,8 @@ var NotificationMessage = new Lang.Class({
     },
 
     _onDestroy() {
+        this.parent();
+
         if (this._updatedId)
             this.notification.disconnect(this._updatedId);
         this._updatedId = 0;