Stderr does not exist as a systemd option (StandardError would've been
correct), but since "journal" is the default by association this mistake
never had any effect. just remove the key entirely.
in some circumstances, the setup service would fail with:
ERROR 1062 (23000) at line 5: Duplicate entry '1' for key 'PRIMARY'
so let's use an upsert instead of insert. This also simplifies the
script.
Besides, also fix that when the setup script changes, the corresponding
script is not restarted as it is usually not active, so we trigger a
restart of the main systemd service.
conversions were done using https://github.com/pennae/nix-doc-munge
using (probably) rev f34e145 running
nix-doc-munge nixos/**/*.nix
nix-doc-munge --import nixos/**/*.nix
the tool ensures that only changes that could affect the generated
manual *but don't* are committed, other changes require manual review
and are discarded.
