Requires revdep-rebuild to trigger rebuild after update to libwebp-0.6.0
commit f64780b95a6cf51e47c365c6ba34631b9dd19649 Author: Alexis Ballier <aballier@gentoo.org> Date: Mon Aug 7 22:39:11 2017 +0200 media-video/ffmpeg: add := dep on webp