[gnome-system-tools] Fix missing cast to OobsGroupsConfig in users-admin

[Milan Bouchet-Valat <milanbv src gnome org>]

commit 2d7c9dfaeb0523216c229a7fb76e29dc97e4584c
Author: Milan Bouchet-Valat <nalimilan club fr>
Date:   Thu Dec 16 12:14:21 2010 +0100

    Fix missing cast to OobsGroupsConfig in users-admin
    
    Removes the only warning left in that tool.

 src/users/user-settings.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/src/users/user-settings.c b/src/users/user-settings.c
index cb15092..219ca62 100644
--- a/src/users/user-settings.c
+++ b/src/users/user-settings.c
@@ -1449,7 +1449,7 @@ on_edit_user_advanced (GtkButton *button, gpointer user_data)
 	/* Leaving user in the password-less login group would still allow him to login,
 	 * which defeats the purpose of disabling account */
 	no_passwd_login_group =
-		oobs_groups_config_get_from_name (GST_USERS_TOOL (tool)->groups_config,
+		oobs_groups_config_get_from_name (OOBS_GROUPS_CONFIG (GST_USERS_TOOL (tool)->groups_config),
 		                                  NO_PASSWD_LOGIN_GROUP);
 	if (password_disabled && no_passwd_login_group)
 		oobs_group_remove_user (no_passwd_login_group, user);