[gnome-build-meta] Update to WebKitGTK 2.25.4

[Michael Catanzaro <mcatanzaro src gnome org>]

commit da9460d4c1d6dfcd9c47e2c7d4c3af7a3cc3f287
Author: Michael Catanzaro <mcatanzaro gnome org>
Date:   Mon Aug 5 10:18:13 2019 -0500

    Update to WebKitGTK 2.25.4

 elements/sdk/WebKitGTK.bst | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/elements/sdk/WebKitGTK.bst b/elements/sdk/WebKitGTK.bst
index cf4f04a6..e099cef9 100644
--- a/elements/sdk/WebKitGTK.bst
+++ b/elements/sdk/WebKitGTK.bst
@@ -1,7 +1,7 @@
 kind: cmake
 sources:
 - kind: tar
-  url: webkitgtk_org:webkitgtk-2.25.3.tar.xz
+  url: webkitgtk_org:webkitgtk-2.25.4.tar.xz
 - kind: patch
   path: files/webkitgtk/gtk-doc-introspection-cross-compiling.patch
 - kind: local