Fix or disable mixed+hs-v2 for Tor 0.3.5
In legacy/trac#33379 (moved), we made some changes that broke mixed+hs-v2 on Tor 0.3.5. Strangely, hs-v2-min works fine.
It looks like it is caused by some microdescriptor download bugs that we fixed in 0.4.0 or 0.4.1.
When we finish the rest of legacy/trac#33232 (moved), or fix legacy/trac#33428 (moved), we should either:
- fix this issue
- require tor or tor-stable to be 0.4.1 or later in mixed+hs-v2