router->address is redundant with router->addr

It used to be more, but these days address is always an IP address, and I believe it always matches router->addr.

So it's only around to save us the trouble of making a string out of ri->addr when we want one. Maybe that's not worth it anymore.

Here are the places where it's set:

In router_parse_entry_from_string():

  router->address = tor_strdup(tok->args[1]);
  if (!tor_inet_aton(router->address, &in)) {
    log_warn(LD_DIR,"Router address is not an IP address.");
    goto err;
  }
  router->addr = ntohl(in.s_addr);

In rewrite_node_address_for_bridge():

        ri->addr = tor_addr_to_ipv4h(&bridge->addr);
        tor_free(ri->address);
        ri->address = tor_dup_ip(ri->addr);

In router_rebuild_descriptor():

  ri->address = tor_dup_ip(addr);
  ri->nickname = tor_strdup(options->Nickname);
  ri->addr = addr;

I think these three might be all the places.