Support disabling addr to hostname lookups

[kode54]

I am finding that depending on the connection, it can take 8-10 seconds before the daemon reads and responds to a query, if it sits there poking the reverse DNS with

oidentd/src/inet_util.c

Line 284 in 3226029

inline int get_hostname(struct sockaddr_storage *addr,

If I could disable this at runtime, I would.

(I am using a layered DNS setup: AdGuard Home -> unbound, or -> dnsmasq for local addresses.)

[kode54]

Yeah, something that would disable this block of code and only print the IP address:

oidentd/src/oidentd.c

Lines 263 to 266 in 3226029

	if (get_hostname(&faddr, host_buf, sizeof(host_buf)) != 0) {
	o_log(LOG_INFO, "Connection from %s:%d", ip_buf, fport);
	xstrncpy(host_buf, ip_buf, sizeof(host_buf));
	} else