MB-100: no need to replicate if srcMeta = destMeta

Change-Id: Id1a62e6d9ded77410ac434a0b675db58ae2b89f4
Reviewed-on: http://review.couchbase.org/30456
Tested-by: Junyi Xie <junyi.couchbase@gmail.com>
Reviewed-by: Junyi Xie <junyi.couchbase@gmail.com>