[gnome-shell] windowManager: Allow toggle-message-tray action in overview

[Florian Müllner <fmuellner src gnome org>]

commit 8aa1765f2420ed06e11f4a75c15a47fdb95bb5c1
Author: Florian Müllner <fmuellner gnome org>
Date:   Fri Mar 6 18:02:57 2015 +0100

    windowManager: Allow toggle-message-tray action in overview
    
    The corresponding action mode was dropped accidentally in commit 08d2e61
    when changing the shortcut to open the calendar drop-down instead.

 js/ui/windowManager.js |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/js/ui/windowManager.js b/js/ui/windowManager.js
index 2691cdb..d04455b 100644
--- a/js/ui/windowManager.js
+++ b/js/ui/windowManager.js
@@ -840,6 +840,7 @@ const WindowManager = new Lang.Class({
                            new Gio.Settings({ schema_id: SHELL_KEYBINDINGS_SCHEMA }),
                            Meta.KeyBindingFlags.NONE,
                            Shell.ActionMode.NORMAL |
+                           Shell.ActionMode.OVERVIEW |
                            Shell.ActionMode.POPUP,
                            Lang.bind(this, this._toggleCalendar));