[gnome-shell] loginDialog: Fix TypeError when user is deleted

[Michael Catanzaro <mcatanzaro src gnome org>]

commit e1e08f0a684281ba4df35d9ce5bc92f0510fd188
Author: Michael Catanzaro <mcatanzaro igalia com>
Date:   Mon Nov 23 17:21:49 2015 -0600

    loginDialog: Fix TypeError when user is deleted
    
    LoginDialog has a private _user, but UserListItem has a public user.
    Easy to get wrong since _user would be the right thing to type in 90% of
    this file.

 js/gdm/loginDialog.js |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/js/gdm/loginDialog.js b/js/gdm/loginDialog.js
index b400d79..4150649 100644
--- a/js/gdm/loginDialog.js
+++ b/js/gdm/loginDialog.js
@@ -96,7 +96,7 @@ const UserListItem = new Lang.Class({
     },
 
     _onDestroy: function() {
-        this._user.disconnect(this._userChangedId);
+        this.user.disconnect(this._userChangedId);
     },
 
     _onClicked: function() {