avoid compile error of opencv_ffmpeg[_64].dll with v2 of FFMPEG wrappers
avoid compile error of opencv_ffmpeg[_64].dll with v2 of FFMPEG wrappers

opencv/opencv,opencv/opencv,opencv/opencv,opencv/opencv,apavlenko/opencv,opencv/opencv,opencv/opencv,apavlenko/opencv,apavlenko/opencv,apavlenko/opencv,apavlenko/opencv,opencv/opencv,opencv/opencv,apavlenko/opencv,opencv/opencv,opencv/opencv