Eliminate the Revert to Default Settings submenu of Option menu.

Not implemented and not needed.
diff --git a/Lib/idlelib/Bindings.py b/Lib/idlelib/Bindings.py
index 2e88c91..e11aec5 100644
--- a/Lib/idlelib/Bindings.py
+++ b/Lib/idlelib/Bindings.py
@@ -70,8 +70,8 @@
    ]),
  ('options', [
    ('_Configure IDLE...', '<<open-config-dialog>>'),
-   None,
-   ('Revert to _Default Settings', '<<revert-all-settings>>'),
+##   None,
+##   ('Revert to _Default Settings', '<<revert-all-settings>>'),
    ]),
  ('help', [
    ('_About IDLE', '<<about-idle>>'),