commit 43c56eb403 introduced a change
where CPUAccounting, CPUAccounting and TasksAccounting are enabled for
the systemd service.
It causes a regression on RHEL 7.8 where systemd-run doesn't allow to
set TasksAccounting.
Since Delegate= already enables all the controllers, it is superfluous
to specify them.
Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>