dirmngr: Auto-switch from Tor port to Torbrowser port.
* dirmngr/dns-stuff.c (libdns_tor_port): New var. (set_dns_nameserver): Clear that var. (libdns_init): Init var to the default port. (libdns_switch_port_p): New func. (resolve_dns_name): Use function to switch the port (get_dns_cert): Ditto. (getsrv): Ditto. (get_dns_cname): Ditto.
- Signed-off-by: Werner Koch <wk@gnupg.org>