CHANGELOG: Add 3.4 changelog entry for lease checkpointing feature
CHANGELOG: Add 3.4 changelog entry for lease checkpointing feature

etcd-io/etcd,etcd-io/etcd,mqliang/etcd,rnaveiras/etcd,li-ang/etcd,gyuho/etcd,coreos/etcd,rnaveiras/etcd,dannysauer/etcd,sinsharat/etcd,coreos/etcd,li-ang/etcd,mqliang/etcd,mkumatag/etcd,vimalk78/etcd,cockroachdb/etcd,joshix/etcd,ajityagaty/etcd,ajityagaty/etcd,mkumatag/etcd,mqliang/etcd,mkumatag/etcd,dannysauer/etcd,xiang90/etcd,cockroachdb/etcd,ajityagaty/etcd,xiang90/etcd,joshix/etcd,gyuho/etcd,rnaveiras/etcd,sinsharat/etcd,etcd-io/etcd,vimalk78/etcd