Run or document about systemctl daemon-reload

[Seb35]

When we run systemctl restart btrfsmaintenance-refresh.service and then systemctl status btrfs-scrub.timer (for instance), there is a warning:

Warning: The unit file, source configuration file or drop-ins of btrfs-scrub.timer changed on disk. Run 'systemctl daemon-reload' to reload units.

Consequently it should either be run systemctl daemon-reload at the end of btrfsmaintenance-refresh-cron.sh or documented to run it. (I’m not sure if it is a good practice to automatically run this command - I don’t know if there could be side-effects on other systemd units.)