CBQE-927: offline upgrade when data removed

Change-Id: I51ff71e9c282527dd9b362ef4b81fd49635a271a
Reviewed-on: http://review.couchbase.org/23879
Reviewed-by: Andrei Baranouski <andrei.baranouski@gmail.com>
Tested-by: buildbot <build@couchbase.com>