vlc: Add ffmpeg version 2.3.x for vlc.

d6821cc9a83f00834f2003d3c6e15597c24421a7 broke vlc. Vlc doesn't support libavcodec >= 56 yet (fails with a configuration error) so it needs an older version of ffpmeg. This patch adds back the 2.3.3 version of ffmpeg so vlc can build against it.

ffmpeg maintainer: @Fuuzetsu