fix sdl pkg-config detection
fix sdl pkg-config detection

siddharudh/mlt,siddharudh/mlt,mltframework/mlt,siddharudh/mlt,mltframework/mlt,mltframework/mlt,siddharudh/mlt,j-b-m/mlt,mltframework/mlt,siddharudh/mlt,siddharudh/mlt,j-b-m/mlt,mltframework/mlt,j-b-m/mlt,j-b-m/mlt,mltframework/mlt,j-b-m/mlt,j-b-m/mlt,mltframework/mlt,mltframework/mlt,siddharudh/mlt,mltframework/mlt,j-b-m/mlt,siddharudh/mlt,mltframework/mlt,j-b-m/mlt,j-b-m/mlt,j-b-m/mlt,siddharudh/mlt