Updated to guildMessageReceivedEvent

src/main/java/net/locusworks/discord/eighttrack/handlers/EightTrackAudioSendHandler.java

@@ -22,6 +22,9 @@ public class EightTrackAudioSendHandler implements AudioSendHandler {
   }
 
   public ByteBuffer provide20MsAudio() {
+    if (lastFrame == null || lastFrame.getData() == null) {
+      return ByteBuffer.wrap(new byte[0]);
+    }
     return ByteBuffer.wrap(lastFrame.getData());
   }