Handle the invalid case of setting multiple stream_bitrates if there is only a single send stream registered.

This can happen when switching between multiple streams and a single while getting feedback from the receiver.

BUG=2881
TEST=trybots
R=mflodman@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/7899004

git-svn-id: http://webrtc.googlecode.com/svn/trunk/webrtc@5486 4adac7df-926f-26a2-2b94-8c16560cd09d
1 file changed