Hide user menu and a11y menu in the screen lock

This is a temporary patch. The user menu button needs to move to
the left, and the a11y menu in some cases needs to be hidden outside
of the screen lock too.

https://bugzilla.gnome.org/show_bug.cgi?id=681143

js/ui/status/accessibility.js

@@ -76,7 +76,7 @@ const ATIndicator = new Lang.Class({
     },
 
     setLockedState: function(locked) {
-        this.menu.setSettingsVisibility(!locked);
+        this.actor.visible = !locked;
     },
 
     _buildItemExtended: function(string, initial_value, writable, on_set) {

js/ui/userMenu.js

@@ -540,9 +540,7 @@ const UserMenuButton = new Lang.Class({
     },
 
     setLockedState: function(locked) {
-        if (locked)
-            this.menu.close();
-        this.actor.reactive = !locked;
+        this.actor.visible = !locked;
     },
 
     _onDestroy: function() {