Whitelisting localhost implicitly whitelists all inbound onion
connections. This prevents banning misbehaving inbound onion peers
and enables message `mempool` which can cause privacy leaks.
Instead, grant `download` as the single bitcoind whitelist permission, which
should be safe for onion peers.
Remove liquidd whitelisting because it doesn't support fine-grained permissions.
After a cursory glance at the nbxplorer code I think that nbxplorer
requires none of the other default whitelist permissions (noban, mempool,
relay).
Details: https://github.com/dgarage/NBXplorer/issues/344