[gnome-system-tools] Fix warning when NO_PASSWD_LOGIN group doesn't exist

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

commit eae5d4be6f5d441feb80800aa6cb2d0580ae9016
Author: Milan Bouchet-Valat <nalimilan club fr>
Date:   Sun Mar 14 15:35:55 2010 +0100

    Fix warning when NO_PASSWD_LOGIN group doesn't exist
    
    We can't assume this group is present on the system.

 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 25e5e94..7845161 100644
--- a/src/users/user-settings.c
+++ b/src/users/user-settings.c
@@ -342,7 +342,7 @@ user_settings_show (OobsUser *user)
 	if (oobs_user_get_password_empty (user))
 		/* TRANSLATORS: This applies to a password. */
 		gtk_label_set_text (GTK_LABEL (passwd_label), _("None"));
-	else if (oobs_user_is_in_group (user, group))
+	else if (group && oobs_user_is_in_group (user, group))
 		/* TRANSLATORS:  This applies to a password. Keep the string short. */
 		gtk_label_set_text (GTK_LABEL (passwd_label), _("Not asked on login"));
 	else