Make all Python pass pyflakes

This found one bug, but will also help us with Jenkins testing of these scripts

Change-Id: Iabe171645c06f769957db7cf0def1d10a0e47988
diff --git a/update_users.py b/update_users.py
index 5ff654b..b40fbfd 100644
--- a/update_users.py
+++ b/update_users.py
@@ -19,6 +19,7 @@
 # 2. split out the two classes into separate files to be used as a library
 
 import os
+import sys
 import ConfigParser
 import StringIO
 import paramiko
@@ -301,7 +302,7 @@
       user_ssh_keys= ["%s %s %s" % ('ssh-%s' % key.keytype.lower(), key.keytext, key.comment) for key in user_data.sshkeys]
       user_email= None
       try:
-        email = user_data.preferred_email_address.email
+        user_email = user_data.preferred_email_address.email
       except ValueError:
         pass
       query= "insert into account_id (s) values (NULL)"