Fix routed(8) remote denial of service vulnerability. [SA-14:21]


git-svn-id: svn+ssh://svn.freebsd.org/base/stable/8@273413 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f
Bump __FreeBSD_version to track SA-14:20, SA-14:21, SA-14:22,
SA-14:23

Approved by:	re (implicit)
Sponsored by:	The FreeBSD Foundation


git-svn-id: svn+ssh://svn.freebsd.org/base/stable/8@273432 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f