systemd: Start processes in forground and without a process group

systemd: Start processes in forground and without a process group

We should not double fork in notify mode or systemd think something
during startup will be wrong and send SIGTERM to the process. So
sometimes the daemon will not start up correctly.

systemd will also handle the process group.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=13129

Signed-off-by: Andreas Schneider <asn@samba.org>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
Autobuild-User(master): Andrew Bartlett <abartlet@samba.org>
Autobuild-Date(master): Tue Nov 28 15:31:27 CET 2017 on sn-devel-144