[gnome-build-meta] Add note to WebKitGTK+.bst

[Michael Catanzaro <mcatanzaro src gnome org>]

commit a8bb39f248d3afc6d5fb250ea28f23f526761c78
Author: Michael Catanzaro <mcatanzaro posteo net>
Date:   Mon Feb 4 19:07:43 2019 +0000

    Add note to WebKitGTK+.bst

 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 f9a412dc..3714adbf 100644
--- a/elements/sdk/WebKitGTK+.bst
+++ b/elements/sdk/WebKitGTK+.bst
@@ -3,7 +3,7 @@ sources:
 - kind: tar
   url: webkitgtk_org:webkitgtk-2.23.3.tar.xz
 # When upgrading to next release:
-# * Remove bug-193903.patch (including from files/)
+# * Remove bug-193903.patch and python3.patch (including from files/)
 # * Add dependency on core-deps/openjpeg.bst
 # * Delete this comment
 # * Remember to create a merge request rather than pushing directly :)