[gnome-sdk-images/gnome-3-26] Update webkitgtk to new security update

[Alexander Larsson <alexl src gnome org>]

commit 64de8ac3699a103cebcbdd4c6da0871c994f45e6
Author: Alexander Larsson <alexl redhat com>
Date:   Wed Oct 18 17:01:33 2017 +0200

    Update webkitgtk to new security update

 org.gnome.Sdk.json.in |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/org.gnome.Sdk.json.in b/org.gnome.Sdk.json.in
index 43c46a5..12a5898 100644
--- a/org.gnome.Sdk.json.in
+++ b/org.gnome.Sdk.json.in
@@ -612,8 +612,8 @@
             "sources": [
                 {
                     "type": "archive",
-                    "url": "https://webkitgtk.org/releases/webkitgtk-2.18.0.tar.xz";,
-                    "sha256": "b583e46a3de36a3e80ba33b084ead60512a2046aca01ff61e50e519436e5038d"
+                    "url": "https://webkitgtk.org/releases/webkitgtk-2.18.1.tar.xz";,
+                    "sha256": "9cdb7b302fbc8a2a7e1e783b80391e64f8b12d70d6ebad4eb756dd59bf3ed795"
                 },
                 {
                     "type": "patch",