Fix failover config for add back test cases

Change-Id: I5df6804717681d52efae685aa3c0a2bb1972ad2a
Reviewed-on: http://review.couchbase.org/35589
Reviewed-by: Parag Agarwal <agarwal.parag@gmail.com>
Reviewed-by: Thuan Nguyen <soccon@gmail.com>
Tested-by: Parag Agarwal <agarwal.parag@gmail.com>