MB-19605: Increase buffer size for addSeqnoVbStats
MB-19605: Increase buffer size for addSeqnoVbStats

The SeqnoVbStats can be greater than 31 characters.
Therefore we need to increase the buffer size.
Increasing to a value of 64.

Change-Id: I43d482630444cb267e4a5f264844cc22a55cd750
Reviewed-on: http://review.couchbase.org/64209
Tested-by: buildbot <80754af91bfb6d1073585b046fe0a474ce868509@couchbase.com>
Reviewed-by: Dave Rigby <a09264da4832c7ff1d3bf1608a19f4b870f93750@couchbase.com>

owendCB/ep-engine,hisundar/ep-engine,membase/ep-engine,hisundar/ep-engine,teligent-ru/ep-engine,daverigby/ep-engine,owendCB/ep-engine,membase/ep-engine,daverigby/kv_engine,daverigby/ep-engine,teligent-ru/ep-engine,membase/ep-engine,couchbase/ep-engine,teligent-ru/ep-engine,hisundar/ep-engine,daverigby/kv_engine,owendCB/ep-engine,teligent-ru/ep-engine,daverigby/kv_engine,daverigby/kv_engine,hisundar/ep-engine,membase/ep-engine,daverigby/ep-engine,owendCB/ep-engine,couchbase/ep-engine,couchbase/ep-engine,couchbase/ep-engine,daverigby/ep-engine