statusMenu: Make "My Account" menu item work again

For GNOME 3.x. gnome-about-me is dead, so we should be using the
user-accounts panel of gnome-control-center instead.

https://bugzilla.gnome.org/show_bug.cgi?id=635264

js/ui/statusMenu.js

@@ -153,7 +153,7 @@ StatusMenuButton.prototype = {
 
     _onMyAccountActivate: function() {
         Main.overview.hide();
-        this._spawn(['gnome-about-me']);
+        this._spawn(['gnome-control-center user-accounts']);
     },
 
     _onPreferencesActivate: function() {