Update the documentation in sip.conf.sample in order to make it more clear
that directmedia/canreinvite do not cause Asterisk to ignore reINVITEs. It
is only used to stop Asterisk from generating a reINVITE, but does not stop
it from accepting them if necessary.
(closes issue #15644)
Reported by: lmadsen
git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@226382 65c4cc65-6c06-0410-ace0-fbb531ad65f3