Fix Ospfd.pm if running with sudo.
ospfd requires owner root and file mode 600 for ospfd.conf
- Fix Typo conftest -> configtest
- Remove existing ospfd.conf before creating a new one because it can be owned
  by root and isn't writable
- In Proc.pm the default grep string for "down" should be "Shutdown" not
  "terminating" (like regress/usr.sbin/relayd/Proc.pm)
add Test args-conftest-ospfd.pl
It starts ospfd in config test mode (-c)