CBQE-2403:: fix condition for bad replicas check

Change-Id: I678a766b3afb0838ec430530509c31bfae68fe60
Reviewed-on: http://review.couchbase.org/41199
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Parag Agarwal <agarwal.parag@gmail.com>
Tested-by: Parag Agarwal <agarwal.parag@gmail.com>