Single onion services and Tor2web connect directly to relays using untrusted link authentication keys. These connections can cause a lot of warnings, particularly due to the link auth bugs in legacy/trac#26627. We can either: * downgrade all link auth warnings to protocol warnings on single onion services and Tor2web (this is the fast fix) * taint untrusted link auth keys, and then downgrade connections using tainted keys to protocol warnings (this is very intrusive)