MB-100: add wait after deinitialize

Change-Id: I39156cdcec12d1d987f77b5b7587eace899a8c3f
Reviewed-on: http://review.couchbase.org/25720
Reviewed-by: Iryna Mironava <irynamironava@yandex.ru>
Tested-by: Iryna Mironava <irynamironava@yandex.ru>