There is no HSDir3 flag, but prop224 says there should be
I think we need to update this part of the proposal to say that a v3 HSDir has:
- the HSDir flag, and
- HSDir protocol version 2, and
- a tor version >= 0.3.0.8.
https://gitweb.torproject.org/torspec.git/tree/proposals/224-rend-spec-ng.txt#n635