Avoid checking ORPort reachability when the network is disabled

This is consistent with existing DirPort reachability checks.

src/or/router.c

@@ -1085,6 +1085,7 @@ check_whether_orport_reachable(void)
 {
   const or_options_t *options = get_options();
   return options->AssumeReachable ||
+         net_is_disabled() ||
          can_reach_or_port;
 }