Revert "package ffmpeg: disable libnut on i686-pc-mingw32"

This reverts commit fc46813219e8d925d3ab54a1d40190d8b805487a.

Some how I forgot to do this during #258.

Signed-off-by: Timothy Gu <timothygu99@gmail.com>
libnut: fix ftello() again

Signed-off-by: Timothy Gu <timothygu99@gmail.com>
Merge pull request #277 from TimothyGu/emerg

Enable libnut/ffmpeg compilation on i686-pc-mingw32 again