[gnome-sdk-images] Update to WebKitGTK+ 2.20.1

[Michael Catanzaro <mcatanzaro src gnome org>]

commit 825d02694000871f824733b4e5a49c766e40e031
Author: Michael Catanzaro <mcatanzaro igalia com>
Date:   Mon Apr 16 11:04:07 2018 -0500

    Update to WebKitGTK+ 2.20.1

 org.gnome.Sdk.json.in | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/org.gnome.Sdk.json.in b/org.gnome.Sdk.json.in
index 67b4978..de22ccb 100644
--- a/org.gnome.Sdk.json.in
+++ b/org.gnome.Sdk.json.in
@@ -821,8 +821,8 @@
             "sources": [
                 {
                     "type": "archive",
-                    "url": "https://webkitgtk.org/releases/webkitgtk-2.20.0.tar.xz";,
-                    "sha256": "57f640f720bd9a8a7207f3321cf803a15c2f207b4e7b75ff1be17bc1eeb00a3c"
+                    "url": "https://webkitgtk.org/releases/webkitgtk-2.20.1.tar.xz";,
+                    "sha256": "43e43285fa4e393080cc4fbd5ad8644749a75b1e0b811b230b63ae56806c8959"
                 }
             ]
         },