always send the leader info on each heartbeat

weed/server/master_grpc_server.go

@@ -66,16 +66,14 @@ func (ms MasterServer) SendHeartbeat(stream pb.Seaweed_SendHeartbeatServer) erro
 			return err
 		}
 
-		if !t.IsLeader() {
-			newLeader, err := t.Leader()
-			if err == nil {
-				if err := stream.Send(&pb.HeartbeatResponse{
-					Leader: newLeader,
-				}); err != nil {
-					return err
-				}
+		// tell the volume servers about the leader
+		newLeader, err := t.Leader()
+		if err == nil {
+			if err := stream.Send(&pb.HeartbeatResponse{
+				Leader: newLeader,
+			}); err != nil {
+				return err
 			}
 		}
-
 	}
 }