CBQE-1408: py-failover.conf without WINDOWS group

Change-Id: I0644f55fef804cdb87a2baf3ba43c8224f86cf31
Reviewed-on: http://review.couchbase.org/28017
Reviewed-by: Andrei Baranouski <andrei.baranouski@gmail.com>
Tested-by: Andrei Baranouski <andrei.baranouski@gmail.com>