[gnome-continuous] Enable webpdemux for WebKitGtk 2.19

[Emmanuele Bassi <ebassi src gnome org>]

commit fd62fd19423cf2925ef63708b2279c70b80acf67
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Mon Dec 4 19:43:33 2017 +0000

    Enable webpdemux for WebKitGtk 2.19

 manifest.json |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)
---
diff --git a/manifest.json b/manifest.json
index 3076665..4b5d55d 100644
--- a/manifest.json
+++ b/manifest.json
@@ -824,7 +824,9 @@
 
                {"src": "fd:geoclue"},
       
-                {"src": "git:https://chromium.googlesource.com/webm/libwebp"},
+                {"src": "git:https://chromium.googlesource.com/webm/libwebp";,
+                 "config-opts": ["--enable-libwebpdemux"]},
+
 
                {"src": "git:https://github.com/hunspell/hunspell.git";,
                  "tag": "2730ad3d32d839f439ba7f286e3600cd9294a978",