[gnome-sdk-images/gnome-3-26] webkitgtk: Fix the tarball sha256

[Mathieu Bridon <mbridon src gnome org>]

commit 80b2bbc75143a1b1f80a891556ac8e8fdc46ca53
Author: Mathieu Bridon <bochecha daitauha fr>
Date:   Mon Jul 16 16:40:32 2018 +0200

    webkitgtk: Fix the tarball sha256
    
    No cause for alarm, Michael confirmed on IRC he had made a mistake and
    used the sha256 for the 2.21.3 tarball.

 org.gnome.Sdk.json.in | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/org.gnome.Sdk.json.in b/org.gnome.Sdk.json.in
index f954192..0edd48c 100644
--- a/org.gnome.Sdk.json.in
+++ b/org.gnome.Sdk.json.in
@@ -670,7 +670,7 @@
                 {
                     "type": "archive",
                     "url": "https://webkitgtk.org/releases/webkitgtk-2.20.3.tar.xz";,
-                    "sha256": "d30dc877f71af260f9f7ce0a75544ee9cc38747b3889023bf7ff4c83e8b2b8dd"
+                    "sha256": "579b307d78fa16a73f112790178022166d7ad17d4147492ced9b9fba48f20dd8"
                 },
                 {
                     "type": "patch",