Adds logging for first time user connections (#78525)

## About The Pull Request

Fikou asked me for this and I like fikou.

![image](https://github.com/tgstation/tgstation/assets/58055496/fdf99821-2404-45c4-ac09-85e29589a7ac)


## Changelog
🆑
admin: First time user connections are now logged
/🆑

code/modules/client/client_procs.dm

@@ -464,6 +464,7 @@ GLOBAL_LIST_INIT(blacklisted_builds, list(
 	var/nnpa = CONFIG_GET(number/notify_new_player_age)
 	if (isnum(cached_player_age) && cached_player_age == -1) //first connection
 		if (nnpa >= 0)
+			log_admin_private("New login: [key_name(key, FALSE, TRUE)] (IP: [address], ID: [computer_id]) logged onto the servers for the first time.")
 			message_admins("New user: [key_name_admin(src)] is connecting here for the first time.")
 			if (CONFIG_GET(flag/irc_first_connection_alert))
 				var/new_player_alert_role = CONFIG_GET(string/new_player_alert_role_id)