CBQE-0:MB-9707: increase sleeping time after deletion is loaded

Change-Id: If630d5d075ae2d26957f03656de828a3c36b43bb
Reviewed-on: http://review.couchbase.org/31270
Reviewed-by: Junyi Xie <junyi.couchbase@gmail.com>
Tested-by: Junyi Xie <junyi.couchbase@gmail.com>