CBQE-1069: added WINDOWS group in py-newupgrade.conf

Change-Id: I0a060e0b057c8ced799f4cf9ac2df65e679b6d55
Reviewed-on: http://review.couchbase.org/25034
Reviewed-by: Andrei Baranouski <andrei.baranouski@gmail.com>
Tested-by: Andrei Baranouski <andrei.baranouski@gmail.com>