Following the upstream documentation for systemd network target:
https://www.freedesktop.org/wiki/Software/systemd/NetworkTarget/
It is not supposed to be used as an active unit and it cannot be started
directly. Quote from the website:
Note that network.target is a passive unit: you cannot start it directly
and it is not pulled in by any services that want to make use of the
network. Instead, it is pulled in by the network management service
itself. Services using the network should hence simply place an
After=network.target dependency in their unit files, and avoid any
Wants=network.target or even Requires=network.target.
This patch changes the documentation to follow the upstream
recommendation.
