Use destination address type in SOCKS5 reply rather than AP address
When replying, checking the address family of the local address only works under the assumption that the local socket type is the same as the destination socket. This was true, until we began supporting AF_UNIX socksports. The result is now that when tor replies to an application over a unix socket, it specifies that it connected to an IPv6 address, when it's possible it connected to an IPv4 address. It seems like a good idea that we base this on the address family of the destination address.