Clean up inactive peers

Wireguard has no logs, but we can keep track of IPs that were connected months ago, even if a peer has become inactive:

wg show wg0

So when you install the script, it would be cool if you could have the option to add a cron entry to clean all the inactive peers every night. That way we don't keep more information than necessary

* 1 * * * /usr/sbin/service wg-quick@wg0 restart >/dev/null 2>&1