More tidying up the (quite) ancient scripts:

* httpd.service no longer uses the apachectl script and now uses the httpd executable instead.
* the netplan 00-installer-config.yaml file had a forgotten change for one of the network adapters.

For the network setup, it's quite jank: IPv4 is handled by netplan and IPv6 is handled by systemd-network. This is due to a historical (2017) setup. Initial IPv4 migration to systemd-network actually broke this a few years ago (around 2019), and I never attempted to fix this since. It should be possible now, though. I also learned to not uninstall netplan at that time...