don't attempt a resolve when the cached answer will do

  o Major bugfixes:

    - For relays that don't know their own address, avoid attempting

      a local hostname resolve for each descriptor we download. Also cut

      down on the number of "Success: chose address 'x.x.x.x'" log lines.

      Fixes bugs 20423 and 20610; bugfix on 0.2.8.1-alpha.

  if (options->BridgeRelay == 1)

    return 0;

  if (server_mode(options) &&

      router_pick_published_address(options, &addr, 0) < 0)

      router_pick_published_address(options, &addr, 1) < 0)

    return 1; /* we don't know our IP address; ask an authority. */

  refuseunknown = ! router_my_exit_policy_is_reject_star() &&

    should_refuse_unknown_exits(options);