relay: Stop advertising HSv2 protocol version

We just disabled v2 in 035+ and so we should make the relays stop advertising the protocol version.

Tor clients don't use protocol versions to learn if a relay can be used for onion service v2 so this shouldn't change much. But it could for any alt-implementation out there that uses those for v2.

Essentially, relay protocol version should be set to:

HSIntro=4-5 -> removing 3 which is v2 specific.
HSDir=2 -> removing 1 which is v2 specific.

Edited Feb 05, 2022 by Roger Dingledine

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information