[gnome-shell] viewSelector: Fix another case of mixing GJS and GObject signals

[Florian Müllner <fmuellner src gnome org>]

commit 0ff5fc8dbba7ac3026b27f81433460d32bb5fc03
Author: Florian Müllner <fmuellner gnome org>
Date:   Thu Feb 23 23:16:07 2017 +0100

    viewSelector: Fix another case of mixing GJS and GObject signals
    
    This is the same issue fixed in commit e08f2a4a041 for several other
    classes, but this one somehow slipped through ...

 js/ui/viewSelector.js |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/js/ui/viewSelector.js b/js/ui/viewSelector.js
index 182d344..211ed42 100644
--- a/js/ui/viewSelector.js
+++ b/js/ui/viewSelector.js
@@ -77,6 +77,7 @@ Signals.addSignalMethods(TouchpadShowOverviewAction.prototype);
 const ShowOverviewAction = new Lang.Class({
     Name: 'ShowOverviewAction',
     Extends: Clutter.GestureAction,
+    Signals: { 'activated': {} },
 
     _init : function() {
         this.parent();
@@ -135,7 +136,6 @@ const ShowOverviewAction = new Lang.Class({
         this.emit('activated', areaDiff);
     }
 });
-Signals.addSignalMethods(ShowOverviewAction.prototype);
 
 const ViewSelector = new Lang.Class({
     Name: 'ViewSelector',