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_gerrit_users.py b/update_gerrit_users.py
index 68ac448..15baaa9 100755
--- a/update_gerrit_users.py
+++ b/update_gerrit_users.py
@@ -19,7 +19,6 @@
 import sys
 import fcntl
 import uuid
-import os
 import subprocess
 
 from datetime import datetime
@@ -42,6 +41,9 @@
 
 DEBUG = False
 
+# suppress pyflakes
+pkg_resources.get_supported_platform()
+
 pid_file = '/tmp/update_gerrit_users.pid'
 fp = open(pid_file, 'w')
 try: