timeadmin should not depend on systemd only

[oz123]

Actual behaviour

The commit 9c2e887
locks timeadmin to systemd systems only.
However, timeadmin only uses known D-Bus services ("org.freedesktop.timedate1.set-time", "org.freedesktop.timedate1.set-timezone" etc...).

Expected behaviour

One should be able to compile timeadmin on systems without systemd.

openrc-settingsd implements these knows services for OpenRC based systems.

https://gitlab.com/postmarketOS/openrc-settingsd/-

One could implement a check if openrc-settingsd is found on the system to enable it.

Steps to reproduce the behavior

Not relevant.

MATE general version

1.29

Package version

1.29

Linux Distribution

PostmarketOS, Gentoo (with OpenRC).

Link to bugreport of your Distribution (requirement)