Party A in an analog 3-way call would continue to hear ringback after party C answers.

Party A in an analog 3-way call would continue to hear ringback after party C answers.

All parties are analog FXS ports.
1) A calls B.
2) A flash hooks to call C.
3) A flash hooks to bring C into 3-way call before C answers.  (A and B hear ringback)
4) C answers
5) A continues to hear ringback during the 3-way call. (All parties can hear each other.)

* Fixed use of wrong variable in dahdi_bridge() that stopped ringback on
the wrong subchannel.

* Made several debug messages have more information.

A similar issue happens if B and C are SIP channels.  B continues to hear
ringback.  For some reason this only affects v1.8 and trunk.

* Don't start ringback on the real and 3-way subchannels when creating the
3-way conference.  Removing this code is benign on v1.6.2 and earlier.

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@293805 65c4cc65-6c06-0410-ace0-fbb531ad65f3