Relays and bridges are not counting directory requests coming in via IPv6

While testing my #8786 (moved) branch I found that relays and bridges are currently not counting directory requests coming in via IPv6 at all. The reason is the if in the following code snippet from directory_handle_command_get():

      struct in_addr in;
      tor_addr_t addr;
      if (tor_inet_aton((TO_CONN(conn))->address, &in)) {
        tor_addr_from_ipv4h(&addr, ntohl(in.s_addr));
        geoip_note_client_seen(GEOIP_CLIENT_NETWORKSTATUS,
                               &addr, NULL,
                               time(NULL));

tor_inet_aton expects an IPv4 address in dotted-quad notation and returns 0 if it's given an IPv6 address.

When digging deeper into Git history, I found that I had changed that code to &TO_CONN(conn)->addr 4 years ago and then again to the code above in 4741aa4 because "Roger notes that address and addr are two different things."

I think this was a mistake and that we can fix this by just reverting 4741aa4. I'll post a branch in a minute that I tested using Chutney's "bridges+ipv6" network (together with teor's #17153 (moved) fix).

Please correct me if we should really use address here instead of addr. In that case we'll probably want to look if address contains an IPv6 address string and handle that separately.