Remove examples of gif_interfaces and gifconfig.  These have already been
marked as deprecated in rc.conf(5) manual page but these examples
were still here.

Spotted by:	jmg


git-svn-id: svn+ssh://svn.freebsd.org/base/head@274841 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f