Don't send two CodecVersion messages

The client is already in the server's list of client and will
get the broadcast message from updateCodecVersions, so we don't
need to send the message twice.

server.go

@@ -294,16 +294,6 @@ func (server *Server) handleAuthenticate(client *Client, msg *Message) {
 	}
 	server.updateCodecVersions()
 
-	err = client.sendProtoMessage(MessageCodecVersion, &mumbleproto.CodecVersion{
-		Alpha:       proto.Int32(server.AlphaCodec),
-		Beta:        proto.Int32(server.BetaCodec),
-		PreferAlpha: proto.Bool(server.PreferAlphaCodec),
-	})
-	if err != nil {
-		client.Panic(err.String())
-		return
-	}
-
 	client.sendChannelList()
 	client.state = StateClientAuthenticated