Use -nofork when starting bosserver via systemd

Systemd does not expect the started process to fork unless
"Type=forking" is given. Use -nofork to run BOS in foreground and allow
systemd to track its state.

Reviewed-on: http://gerrit.openafs.org/10087
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@your-file-system.com>
Reviewed-by: Marc Dionne <marc.c.dionne@gmail.com>
Reviewed-by: Mark Vitale <mvitale@sinenomine.net>
Tested-by: Michael Laß <lass@mail.uni-paderborn.de>
Tested-by: Ken Dreyer <ktdreyer@ktdreyer.com>
Reviewed-by: Ken Dreyer <ktdreyer@ktdreyer.com>
(cherry picked from commit e2d458c11956af6fe721f7151487cb19f07ac16f)

Change-Id: I2b66ca126dbda6c2c616d74b571908c57d1e86e4
Reviewed-on: http://gerrit.openafs.org/10093
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Ken Dreyer <ktdreyer@ktdreyer.com>
Reviewed-by: Andrew Deason <adeason@sinenomine.net>
Reviewed-by: Stephan Wiesand <stephan.wiesand@desy.de>