Remove channel limitation in mythtranscode

Should fix #9414. I don't understand why this would have ever worked in the past. But if it did, it was just lucky. So we just push our luck further

mythtv/programs/mythtranscode/transcode.cpp

@@ -59,13 +59,10 @@ class AudioReencodeBuffer : public AudioOutput
     virtual void Reconfigure(const AudioSettings &settings)
     {
         ClearError();
-        bytes_per_frame = channels *
-                           AudioOutputSettings::SampleSize(settings.format);
 
         channels = settings.channels;
-
-        if ((uint)settings.channels > 2)
-            Error(QString("Invalid channel count %1").arg(channels));
+        bytes_per_frame = channels *
+                           AudioOutputSettings::SampleSize(settings.format);
     }
 
     // dsprate is in 100 * samples/second