Merge commit '01947f07b81a57fb1e15114b710f6d5ae4f70a11'

* commit '01947f07b81a57fb1e15114b710f6d5ae4f70a11':
  avconv: remove a useless line

Merged-by: Michael Niedermayer <michaelni@gmx.at>

ffmpeg.c

@@ -1672,7 +1672,6 @@ static void do_streamcopy(InputStream *ist, OutputStream *ost, const AVPacket *p
     }
 
     write_frame(of->ctx, &opkt, ost);
-    ost->st->codec->frame_number++;
 }
 
 int guess_input_channel_layout(InputStream *ist)