fix(network): ignore connections from the node to itself

[laplab]

alice example with the following config:

[system.telemeters]
sink = "Prometheus"
address = "0.0.0.0:9100"

[system.dumpers]
path = "example.alice.{class}.dump"

[system.network]
listen = ["tcp://127.0.0.1:9200"]
# note that discovery is set to the same address as the listen section
discovery.predefined = ["tcp://127.0.0.1:9200"]

Results in the following behaviour:

2023-06-14 10:47:14.623828000  INFO [2478858310674023425] system.network.discovery - new connection established peer=tcp://127.0.0.1:59137  role=Unknown
2023-06-14 10:47:14.623879000  INFO [2478858310674022401] system.network.discovery - new connection established peer=tcp://127.0.0.1:9200   role=Control
2023-06-14 10:47:14.624362000 DEBUG [2478858310674022401] system.network.discovery - handshake succeeded    peer=tcp://127.0.0.1:59137  elapsed=435.83µs
2023-06-14 10:47:14.624374000 DEBUG [2478858310674022401] system.network.discovery - connection to self ignored peer=tcp://127.0.0.1:59137
2023-06-14 10:47:14.624492000 DEBUG [2478858310674023425] system.network.discovery - handshake succeeded    peer=tcp://127.0.0.1:9200   elapsed=478.306µs
2023-06-14 10:47:14.624502000 DEBUG [2478858310674023425] system.network.discovery - connection to self ignored peer=tcp://127.0.0.1:9200

peer=tcp://127.0.0.1:59137 is the listener ignoring the request and peer=tcp://127.0.0.1:9200 is the discovery ignoring the request.