I need unisolated port for dnscrypt-proxy which I fear would otherwise
generate too many circuits which wouldn't even be used and I guess
there is no harm in sending Yggdrasil to a separate port that only has
access to onions which is a port I may sometimes wish I have otherwise
too.
> The ClientPreferIPv6DirPort option is deprecated, and will most likely be removed in a future version of Tor. It has no effect on relays, and has had no effect on clients since 0.2.8. (If you think this is a mistake, please let us know!)
