Accept MP3 as an alternative to MPGA for RTP and TS.

Someone please double check that this is not bogus!

modules/mux/mpeg/ts.c

@@ -956,6 +956,7 @@ static int AddStream( sout_mux_t *p_mux, sout_input_t *p_input )
             switch( p_input->p_fmt->i_codec )
             {
                 case VLC_FOURCC( 'm', 'p','g', 'a' ):
+                case VLC_FOURCC( 'm', 'p', '3', ' ' ):
                     p_stream->i_stream_type =
                         p_input->p_fmt->audio.i_rate >= 32000 ? 0x03 : 0x04;
                     p_stream->i_stream_id = 0xc0;

modules/stream_out/rtp.c

@@ -962,6 +962,7 @@ static sout_stream_id_t *Add( sout_stream_t *p_stream, es_format_t *p_fmt )
             id->pf_packetize = rtp_packetize_l8;
             break;
         case VLC_FOURCC( 'm', 'p', 'g', 'a' ):
+        case VLC_FOURCC( 'm', 'p', '3', ' ' ):
             id->i_payload_type = 14;
             id->psz_enc = "MPA";
             id->pf_packetize = rtp_packetize_mpa;