Authorities shouldn't set Running unless all advertised OR ports are reachable

Prop 186 says

An authority shouldn't list a node as Running unless every or-address line it advertises looks like it will work.

Authorities don't consider a potential IPv6 OR port when deciding whether a relay is running or not.

I suggest we fix that but have auths not on IPv6 (AuthDirHasIPv6Connectivity == 0) not take IPv6 reachability into account.