All these entities are not been used anywhere.
* nix/libstore/globals.hh (Settings): Remove 'overrides' member
and 'getOverrides' method declaration.
(nixVersion): Removed.
* nix/libstore/globals.cc (Settings::set): Do not update the 'overrides' map.
(Settings::getOverrides): Remove function definition.
Change-Id: If7dbb6df79178d2569cda21e1fe5e0ea3d8e59ba
Signed-off-by: Ludovic Courtès <ludo@gnu.org>
Merges: #6009