CCBC-609, CCBC-612: Handle topology changes with non-data nodes
CCBC-609, CCBC-612: Handle topology changes with non-data nodes

While the lcbvb subsystem can properly parse configurations without data
nodes, some other code, namely those which depend on reusing data node
connections, would crash.

This fixes the issue by simply assuming there are no equivalencies.

Change-Id: If253c5c68c19a1899d01af06dcf2376f1ea3c533
Reviewed-on: http://review.couchbase.org/51371
Tested-by: buildbot <80754af91bfb6d1073585b046fe0a474ce868509@couchbase.com>
Reviewed-by: Subhashni Balakrishnan <7129c8e37b832c7bd362ff375532d24b98ef5162@gmail.com>

senthilkumaranb/libcouchbase,signmotion/libcouchbase,kojiromike/libcouchbase,mody/libcouchbase,avsej/libcouchbase,couchbase/libcouchbase,avsej/libcouchbase,avsej/libcouchbase,couchbase/libcouchbase,maxim-ky/libcouchbase,avsej/libcouchbase,mody/libcouchbase,couchbase/libcouchbase,couchbase/libcouchbase,senthilkumaranb/libcouchbase,PureSwift/libcouchbase,mody/libcouchbase,avsej/libcouchbase,PureSwift/libcouchbase,signmotion/libcouchbase,avsej/libcouchbase,maxim-ky/libcouchbase,couchbase/libcouchbase,PureSwift/libcouchbase,PureSwift/libcouchbase,senthilkumaranb/libcouchbase,signmotion/libcouchbase,couchbase/libcouchbase,senthilkumaranb/libcouchbase,couchbase/libcouchbase,maxim-ky/libcouchbase,kojiromike/libcouchbase,signmotion/libcouchbase,kojiromike/libcouchbase,avsej/libcouchbase,mody/libcouchbase,kojiromike/libcouchbase,maxim-ky/libcouchbase