[sysadmin-bin] Fix the same crash as a72bd46 on create-auth

[Andrea Veri <av src gnome org>]

commit a40b84dea9da7db572c01759ecddc9185f216c04
Author: Andrea Veri <av gnome org>
Date:   Fri Mar 20 19:06:02 2015 +0100

    Fix the same crash as a72bd46 on create-auth

 create-auth |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/create-auth b/create-auth
index 39b9941..0ff4f40 100755
--- a/create-auth
+++ b/create-auth
@@ -64,6 +64,9 @@ def _get_group_from_ldap(group):
     members = set()
 
     for _, attr in results:
+        if 'member' not in attr:
+            continue
+
         for userid in attr['member']:
             splitentry = userid.split(',')
             singleentry = splitentry[0]