datetime: Avoid error when systemctl is not available
This situation happens when building the package with cowbuilder.
Tests:
- Previous error during build is fixed:
changing mode of /build/freedombox-21.13/debian/tmp/usr/bin/plinth to 755
./run --develop --list-dependencies | sort | tr '\n' ', ' | \
sed -e 's/^/freedombox:Depends=/' >> debian/freedombox.substvars
make[1]: Leaving directory '/build/freedombox-21.13'
- Built .deb package has dependency on apache2, certbot, cockpit, etc.
Signed-off-by: James Valleroy jvalleroy@mailbox.org
Edited by James Valleroy