CBQE-0: fix failing rebalance-in-out tests

Change-Id: I0610aed12b939324933323ca3d03496b58ae67c8
Reviewed-on: http://review.couchbase.org/40597
Reviewed-by: Thuan Nguyen <soccon@gmail.com>
Reviewed-by: Parag Agarwal <agarwal.parag@gmail.com>
Tested-by: Parag Agarwal <agarwal.parag@gmail.com>