StoreTask: send heartbeat when commit the replicat task

go/storage/store_task_replication.go

@@ -89,6 +89,7 @@ func (t *ReplicaTask) Commit() error {
 	volume, e = NewVolume(t.location.Directory, t.Collection, t.VID, t.s.needleMapKind, nil)
 	if e == nil {
 		t.location.volumes[t.VID] = volume
+		t.s.SendHeartbeatToMaster()
 	}
 	return e
 }