Wrapping an LSB init script with systemd-sysv-generator(8) is not an ideal way to run a system service. In particular, systemd-sysv-generator can't tell whether an init script is meant to be the equivalent of systemd Type=forking (like /etc/init.d/dbus) or the equivalent of systemd Type=oneshot (like /etc/init.d/sudo), so it has no choice but to create a weird mixture of the two which doesn't reliably detect errors.

I suspect that a future version of systemd will deprecate systemd-sysv-generator and stop installing it by default, although I don't think any such plans have been announced yet.

Here's a native systemd unit equivalent of the LSB init script, which is much shorter and simpler than the init script itself: https://git.pseudorandom.co.uk/smcv/ikiwiki-hosting.git/shortlog/refs/heads/native-systemd-unit

I haven't removed the LSB init script, so users of non-systemd init can continue to use it as-is.