CBQE-0: fix hostname mgmt failover test

Change-Id: I15744e3d132e79b21f6c990ae8450c9040542d53
Reviewed-on: http://review.couchbase.org/42330
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Meenakshi Goel <meenakshi.goel@globallogic.com>
Tested-by: Meenakshi Goel <meenakshi.goel@globallogic.com>