This PR upgrades `litep2p` to the latest version and includes the two
fixes:

1. Enables incoming DHT record validation with `litep2p` network
backend.
2. Sets `TCP_NODELAY` flag on TCP & WS sockets in `litep2p` backend, as
it is currently done in `libp2p` backend.

---------

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>
Co-authored-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>