[cache-service] Return dummy topology warning.
[cache-service] Return dummy topology warning.

Change-Id: I0d5ba69bd6ed1b5e3445f6443698e1ea97a5ab96
Reviewed-on: http://review.couchbase.org/62146
Tested-by: Aliaksey Artamonau <3c875bcfb3adf2a65b2ae7686ca921e6c9433147@gmail.com>
Reviewed-by: Artem Stemkovski <15a0730a27c69f62ab86f2b6c639fca202166c02@couchbase.com>

couchbase/cbauth,couchbase/cbauth