contrib: ffmpeg was removed from libav

(cherry picked from commit c48f8460)
Signed-off-by: Rafaël Carré <funman@videolan.org>

contrib/src/ffmpeg/rules.mak

@@ -12,7 +12,6 @@ FFMPEGCONF = \
 	--disable-debug \
 	--enable-gpl \
 	--enable-postproc \
-	--disable-ffmpeg \
 	--disable-avconv \
 	--disable-devices \
 	--disable-protocols \