Does the `yggdrasil_only` option make any sense?

[oooo-ps]

I made a local patch that extends configuration file with an additional Mycelium network filter.

However, before making a new PR, I understand that it doesn't make sense because this filter is applied after the connection is established (to detect the peer address). In other words, when this option is enabled, it simply closes the existing connection using stream.shutdown(Shutdown::Both) socket API.

Therefore, I might consider using firewall rules, as the current implementation just skips handling the request instead of receiving the peer request. Maybe it's better to remove yggdrasil_only option in future releases instead of extending it.

UPD. it's the same confusing situation as with the Bitcoin options, which are applicable only for outgoing connections to peers that come from trackers, seeds, or public peers.