Remove some old code for going to the 'fax' extension when a T.38 switchover...

Remove some old code for going to the 'fax' extension when a T.38 switchover occurs. This would have
already happened when we detected the CNG tone so this was basically a noop.


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@235521 65c4cc65-6c06-0410-ace0-fbb531ad65f3