fixing https://freedesktop.org/bugzilla/show_bug.cgi?id=1563

[xorg/xkeyboard-config] / types / mousekeys

// $Xorg: mousekeys,v 1.3 2000/08/17 19:54:48 cpqbld Exp $
// 
partial default xkb_types "default" {
    virtual_modifiers Alt;

    type "SHIFT+ALT" {
        modifiers = Shift+Alt;
        map[Shift+Alt] = Level2;
        level_name[Level1] = "Base";
        level_name[Level2] = "Shift+Alt";
    };
};