Fix propagating RED paylaod-type to ACM.

BUG=issue1322
TBR=henrika@google.com
Review URL: https://webrtc-codereview.appspot.com/1086005

git-svn-id: http://webrtc.googlecode.com/svn/trunk/webrtc@3449 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/voice_engine/channel.cc b/voice_engine/channel.cc
index 1ffc4d0..dd0423f 100644
--- a/voice_engine/channel.cc
+++ b/voice_engine/channel.cc
@@ -6701,6 +6701,7 @@
     return -1;
   }
 
+  codec.pltype = red_payload_type;
   if (_audioCodingModule.RegisterSendCodec(codec) < 0) {
     _engineStatisticsPtr->SetLastError(
         VE_AUDIO_CODING_MODULE_ERROR, kTraceError,