ffmpeg_opt: Move the 'process manually set programs' block above 'process...

ffmpeg_opt: Move the 'process manually set programs' block above 'process manually set metadata' in open_output_file().

Signed-off-by: Vittorio Gambaletta <ffmpeg-dev@vittgam.net>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>