MB-15699: Log before we assert due to invalid lastBySeqno in queueDirty()
MB-15699: Log before we assert due to invalid lastBySeqno in queueDirty()

This would be helpful to debug corner cases causing this assertion

Change-Id: I55659e30e5d20e116dfb7abf1b1df2b4c5357c8e
Reviewed-on: http://review.couchbase.org/53314
Tested-by: buildbot <80754af91bfb6d1073585b046fe0a474ce868509@couchbase.com>
Reviewed-by: Chiyoung Seo <fcffc23db27b19ee4ebba46695ee6b50e09216a2@couchbase.com>

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