skip ext header missing message for msmpeg4v2

Originally committed as revision 2118 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/msmpeg4.c

@@ -1409,6 +1409,7 @@ int msmpeg4_decode_ext_header(MpegEncContext * s, int buf_size)
     else if(left<length+8)
     {
         s->flipflop_rounding= 0;
+        if(s->msmpeg4_version != 2)
             printf("ext header missing, %d left\n", left);
     }
     else