[gtk-doc] docs: update sgml todos

[Stefan Sauer <stefkost src gnome org>]

commit 49872eb44af0e14eaa7e5df1f1ef20382e615f8a
Author: Stefan Sauer <ensonic users sf net>
Date:   Wed Mar 22 09:29:30 2017 +0100

    docs: update sgml todos

 doc/design-2.x.txt |    3 +--
 1 files changed, 1 insertions(+), 2 deletions(-)
---
diff --git a/doc/design-2.x.txt b/doc/design-2.x.txt
index 04cffb6..143440f 100644
--- a/doc/design-2.x.txt
+++ b/doc/design-2.x.txt
@@ -7,8 +7,7 @@ Its not about Gtk. Its about C APIs with GObject support.
 g-doc, gapi-doc, gnome-api-doc, ...
 
 == remove and deprecate =
-- rename generated index.sgml to something like index.idx - it is not wellformed
-  sgml
+- tree_index and object_index are still named *.sgml
 - in the makefiles
   sgml-build.stamp -> db-build.stamp
   sgml.stamp -> db.stamp