This is a small update to PLIST that comments mgettydefs man page. Indeed, this
feature is not build by default, so there's no need for the man page.
Thanks to Matthias Kilian <kili at outback dot escape dot de> telling me this
man page was not in the correct section, he made me realized this man page was
in fact not needed at all ;)
# strings /usr/local/sbin/mgetty | grep gettydefs
gettydefs not supported