CBQE-0: fix TimeoutError in incremental_rebalance_in_out_with_mutation_and_expiration

Change-Id: I4a4ef7f165077d55938881c0b7c4331026d241b2
Reviewed-on: http://review.couchbase.org/32901
Reviewed-by: Iryna Mironava <irynamironava@yandex.ru>
Tested-by: Andrei Baranouski <andrei.baranouski@gmail.com>