Set Restart Flag after Add/Del Bucket

It is mandatory to set Restart flag if adding or
deleting a bucket from a stream

Change-Id: I7ed1516bc7e0c5882e4473a401ff71640fb29c87
Reviewed-on: http://review.couchbase.org/41415
Reviewed-by: Deepkaran Salooja <deepkaran.couchbase@gmail.com>
Tested-by: Deepkaran Salooja <deepkaran.couchbase@gmail.com>