Failed node self-test results in segfault

[amirylm]

On startup the ssv-node makes a self-check and tries to connect to itself when the host-address flag is set. Regardless whether the connection fails, it wants to close the connection, resulting in a segfault if the connection couldnt be established beforehand (L169 p2p.go).

Either gracefully shutdown if selfcheck fails or give a warning and resume. The latter would be the preferred way for me because there seems to be situation where only the self-check fails but it operates fine in the wild.

The issue with not being able to establish a connection to itself via vpn is a known issue on prysm as well and I have a similar warning during startup there as well. See eg prysmaticlabs/prysm#7724 That said, Prysm works fine anyway for me with a similar setup. I can also connect to other peers with the ssv node.