CBQE-1468: add reproducer for MB-7764

Change-Id: If382fd2400cc176410e12aaf0b26b6fa6e28fd46
Reviewed-on: http://review.couchbase.org/39074
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Iryna Mironava <irynamironava@yandex.ru>