MB-5688 Don't notify_update for checkpointId only change
MB-5688 Don't notify_update for checkpointId only change

Local doc update with checkpointId only change, and it'd be waste
to send notify_update to mccouch.

Change-Id: I02db641089624179157cf653c7cab2c8ba96fa78
Reviewed-on: http://review.couchbase.org/17618
Tested-by: Chiyoung Seo <8b279095f11c26cc21045fda5a3e51debb005aa9@gmail.com>
Reviewed-by: Chiyoung Seo <8b279095f11c26cc21045fda5a3e51debb005aa9@gmail.com>

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