CBQE-2053: add vbuckets shuffling chack for online upgrade

Change-Id: I67afec7e423ebef9ff23a5a5741fb31f0e768a4b
Reviewed-on: http://review.couchbase.org/33794
Reviewed-by: Andrei Baranouski <andrei.baranouski@gmail.com>
Tested-by: buildbot <build@couchbase.com>