gnu: x265: Update to 2.8.

* gnu/packages/video.scm (x265): Update to 2.8.

gnu/packages/video.scm

@@ -380,7 +380,7 @@ and creating Matroska files from other media files (@code{mkvmerge}).")
 (define-public x265
   (package
     (name "x265")
-    (version "2.7")
+    (version "2.8")
     (source
       (origin
         (method url-fetch)
@@ -388,7 +388,7 @@ and creating Matroska files from other media files (@code{mkvmerge}).")
                             "x265_" version ".tar.gz"))
         (sha256
          (base32
-          "18llni1m8kfvdwy5bp950z6gyd0nijmvi3hzd6gd8vpy5yk5zrym"))
+          "0qx8mavwdzdpkkby7n29i9av7zsnklavacwfz537mf62q2pzjnbf"))
         (modules '((guix build utils)))
         (snippet
          '(begin