[gnome-shell] screenShield: Fix regression from 114f6f577f58

[Florian MÃllner <fmuellner src gnome org>]

commit 23c1138a5809337d4039b85de78b6c1c85b0770f
Author: Florian MÃllner <fmuellner gnome org>
Date:   Wed Sep 19 13:11:27 2012 +0200

    screenShield: Fix regression from 114f6f577f58

 js/ui/screenShield.js |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)
---
diff --git a/js/ui/screenShield.js b/js/ui/screenShield.js
index 96e2f80..ff410c8 100644
--- a/js/ui/screenShield.js
+++ b/js/ui/screenShield.js
@@ -698,9 +698,10 @@ const ScreenShield = new Lang.Class({
     },
 
     _lockScreenShown: function() {
-        if (this._dialog)
+        if (this._dialog && !this._isGreeter) {
             this._dialog.destroy();
-        this._dialog = null;
+            this._dialog = null;
+        }
 
         if (this._arrowAnimationId)
             Mainloop.source_remove(this._arrowAnimationId);