PopupSwitchMenuItem: don't override switch by creating it twice

Due to an accidental addition line in commit c8670819, all switches in popup
menus accidentally gave the appearance that they were turned off.

Signed-off-by: Marc-Antoine Perennou <Marc-Antoine@Perennou.com>

https://bugzilla.gnome.org/show_bug.cgi?id=654267

js/ui/popupMenu.js

@@ -711,7 +711,6 @@ PopupSwitchMenuItem.prototype = {
         this._statusLabel = new St.Label({ text: '',
                                            style_class: 'popup-inactive-menu-item'
                                          });
-        this._switch = new Switch(false);
         this._statusBin.child = this._switch.actor;
     },