From man page:
```
deb-systemd-invoke is a Debian-specific helper script which asks
/usr/sbin/policy-rc.d before performing a systemctl call.
deb-systemd-invoke is intended to be used from maintscripts to start
systemd unit files. It is specifically NOT intended to be used
interactively by users. Instead, users should run systemd and use
systemctl, or not bother about the systemd enabled state in case they
are not running systemd.
```
This PR replace regular `systemctl` with `deb-systemd-invoke`.
9c45a2150d