Update to revision r40649:
Correct the example on how to prevent NIS users from logging in.  The
previous instructions did not work and this corrected version is based on
a working config from a production system.  Add some descriptive text, too.

Submitted by:	Bjoern Heidotting
Obtained from:	The FreeBSD German Documentation Project


git-svn-id: svn+ssh://svn.freebsd.org/doc/head@45643 c2e8774f-c49f-e111-b436-862b2bbc8956
Put in the missing revision r40833:
Remove mention of plip0, the parallel-port network device.

Submitted by:	    Bjoern Heidotting
Obtained from:	    The FreeBSD German Documentation Project


git-svn-id: svn+ssh://svn.freebsd.org/doc/head@45644 c2e8774f-c49f-e111-b436-862b2bbc8956