Bug 1418252 - Add missing 'sys' import. r=jmaher

--HG--
extra : rebase_source : c35fe0d1289aee2f81af7b67548f8ed98c349e07

testing/mozharness/configs/talos/windows_taskcluster_config.py

@@ -1,5 +1,6 @@
 import os
 import socket
+import sys
 
 PYTHON = sys.executable
 PYTHON_DLL = 'c:/mozilla-build/python/python27.dll'