CBQE-1331: test hangs on rebalance out when ejected node is unavalable

Change-Id: I1f900bd80deef3ddcb377cde34680cccbbf0f4f6
Reviewed-on: http://review.couchbase.org/26833
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Andrei Baranouski <andrei.baranouski@gmail.com>
Tested-by: Andrei Baranouski <andrei.baranouski@gmail.com>