[BUG] DHT Join may not work properly

[RyanKung]

    #[tokio::test]
    async fn test_31d_41d() -> Result<()> {
	let did_1d = Did::from_str("0x32d9f459e066d1855b138d23733e4cd85fd3b7c7")?;
	let did_2d = Did::from_str("0xc63fb6194b7f253404632fdce7c7ff1ce24b6ab3")?;
	let did_31d = Did::from_str("0x99fee2794a7e3067bb97e17cb7d7fc551c596f9f")?;
	let did_41d = Did::from_str("0x0298ba2b72ef040bbd99398f96594e8d8c0d0607")?;

	let dht_1d = gen_pure_dht(did_1d).await?;
	let dht_2d = gen_pure_dht(did_2d).await?;
	let dht_31d = gen_pure_dht(did_31d).await?;
	let dht_41d = gen_pure_dht(did_41d).await?;

	dht_31d.join(did_1d)?;
	dht_31d.join(did_2d)?;

	dht_1d.join(did_31d)?;
	dht_2d.join(did_31d)?;
	{
	    let finger_31d = dht_31d.lock_finger()?;

	    assert!(finger_31d.contains(Some(did_1d)));
	    assert!(finger_31d.contains(Some(did_2d)));
	}
	let ret = dht_41d.join(did_31d).unwrap();
        assert_eq!(
            ret,
            PeerRingAction::RemoteAction(did_31d, RemoteAction::FindSuccessorForConnect(did_41d))
        );
	{
	    let finger_31d = dht_31d.lock_finger().unwrap();
	    assert!(finger_31d.contains(Some(did_1d)));
	    assert!(finger_31d.contains(Some(did_2d)));
	    assert_eq!(finger_31d.closest_predecessor(did_41d), did_2d);
	}

	let ret = dht_31d.find_successor(did_41d).unwrap();
        assert_eq!(
            ret,
            PeerRingAction::RemoteAction(did_2d, RemoteAction::FindSuccessor(did_41d))
        );

	dht_2d.join(did_1d)?;
	{
	    let finger_2d = dht_2d.lock_finger().unwrap();
	    assert!(finger_2d.contains(Some(did_1d)), "{:?}", finger_2d.list());
	}


	let ret = dht_2d.find_successor(did_41d).unwrap();
	assert_eq!(
            ret,
            PeerRingAction::Some(did_1d)
        );

	Ok(())
    }

[RyanKung]

This issue will be handle by #388 #448