MB-9548 delete all replications from the bucket

... before deleting the bucket

Change-Id: I4fc0f81ed243ebbb2bed99cb79865bf403e68026
Reviewed-on: http://review.couchbase.org/30750
Tested-by: Artem Stemkovski <artem@couchbase.com>
Reviewed-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>