BUG/MEDIUM: remove debugging code from systemd-wrapper

Kristoffer Grönlund reported that after my recent update to the
systemd-wrapper, I accidentely left the debugging code which
consists in disabling the fork :-(

The fix needs to be backported to 1.5 as well since I pushed it
there as well.
(cherry picked from commit a55bbc64d8272e4066a67b6d190ffebaff2b300a)