Fix Sanity Test config for Failover

Change-Id: Ie73561705a59363cbb3b62af8fa6d41de6bf9da8
Reviewed-on: http://review.couchbase.org/35591
Reviewed-by: Parag Agarwal <agarwal.parag@gmail.com>
Tested-by: Parag Agarwal <agarwal.parag@gmail.com>