systemd: Little allocation improvement

Signed-off-by: Quentin Glidic <sardemff7+git@sardemff7.net>
systemd: Properly free the config file

Signed-off-by: Quentin Glidic <sardemff7+git@sardemff7.net>
systemd: Do not output error if the unit is not available

Signed-off-by: Quentin Glidic <sardemff7+git@sardemff7.net>
systemd: Do not trach the D-Bus name any more

systemd should always be here anyway.

Signed-off-by: Quentin Glidic <sardemff7+git@sardemff7.net>
systemd: Get/drop unit status on start/stop

Signed-off-by: Quentin Glidic <sardemff7+git@sardemff7.net>
systemd: Get/drop unit status on systemd reload

Signed-off-by: Quentin Glidic <sardemff7+git@sardemff7.net>
j4status: Correctly free the plugin struct

Signed-off-by: Quentin Glidic <sardemff7+git@sardemff7.net>