dirmngr: Pass Tor credentials to libdns.
* dirmngr/dns-stuff.c (tor_credentials): Replace by ... (tor_socks_user, tor_socks_password): new vars. (enable_dns_tormode): Set these new vars. (libdns_res_open): Tell libdns the socks credentials.
- Signed-off-by: Werner Koch <wk@gnupg.org>