[gnome-shell] messageTray: don't accidentally shift the tray around in the overview

[Giovanni Campagna <gcampagna src gnome org>]

commit d053d45a6dbd7eda26418b34a232536823c0d399
Author: Sebastian Keller <sebastian-keller gmx de>
Date:   Sun Nov 18 02:01:00 2012 +0100

    messageTray: don't accidentally shift the tray around in the overview
    
    https://bugzilla.gnome.org/show_bug.cgi?id=688422

 js/ui/messageTray.js |    3 +--
 1 files changed, 1 insertions(+), 2 deletions(-)
---
diff --git a/js/ui/messageTray.js b/js/ui/messageTray.js
index 1617490..8fbc0b2 100644
--- a/js/ui/messageTray.js
+++ b/js/ui/messageTray.js
@@ -2013,8 +2013,7 @@ const MessageTray = new Lang.Class({
         let summaryPinned = this._pointerInTray || summarySummoned || this._locked;
         let summaryHovered = this._pointerInTray || this._pointerInSummary;
 
-        let notificationsVisible = (this._notificationState == State.SHOWING ||
-                                    this._notificationState == State.SHOWN);
+        let notificationsVisible = this._notificationState != State.HIDDEN;
         let notificationsDone = !notificationsVisible && !notificationsPending;
 
         let summaryOptionalInOverview = this._overviewVisible && !this._locked && !summaryHovered;