contrib/ffmpeg: disable postproc

Change-Id: Iec9409a6d25e028b5d2fb7c3afb0cde832383c14
Reviewed-by: Philippe Gorley <philippe.gorley@savoirfairelinux.com>

contrib/src/ffmpeg/rules.mak

@@ -22,7 +22,8 @@ FFMPEGCONF += \
 	--enable-protocols \
 	--enable-bsfs \
 	--enable-filters \
-	--disable-programs
+	--disable-programs \
+	--disable-postproc
 
 #enable muxers/demuxers
 FFMPEGCONF += \