* client/authority-discovery: Don't add own address to priority group
In the scenario of a validator publishing the address of its sentry node
to the DHT, said sentry node should not add its own Multiaddr to the
peerset "authority" priority group.
Related to 273f31b.
* client/authority-discovery: Remove unused import PeerId
* client/authority-discovery/tests: Add tcp protocol to multiaddresses