[gnome-sdk-images/gnome-3-26] Upgrade to WebKitGTK+ 2.20.5

[Michael Catanzaro <mcatanzaro src gnome org>]

commit 8c53e76c9f9fa4c01fde4d5d7654d607add4d2b8
Author: Michael Catanzaro <mcatanzaro igalia com>
Date:   Mon Aug 13 09:51:29 2018 -0500

    Upgrade to WebKitGTK+ 2.20.5

 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 a94ea8c..ceed075 100644
--- a/org.gnome.Sdk.json.in
+++ b/org.gnome.Sdk.json.in
@@ -673,8 +673,8 @@
             "sources": [
                 {
                     "type": "archive",
-                    "url": "https://webkitgtk.org/releases/webkitgtk-2.20.4.tar.xz";,
-                    "sha256": "cc7dd15505c4f8a75d96deae148a82d7cc9034c7f3cc8a1fe4f969dddd92ae32"
+                    "url": "https://webkitgtk.org/releases/webkitgtk-2.20.5.tar.xz";,
+                    "sha256": "15c0f8d26e9605afe0948d161ba5fd82efee8eda2debd409fd40a440ac3af990"
                 },
                 {
                     "type": "patch",