[InnoSetup] Ask for delete config file on uninstall

delete-config.iss

#define SettingsFile "settings.xml"

[CustomMessages]
english.DeleteSettings=Delete settings file?

[Code]
// ask for delete config file during uninstall
procedure CurUninstallStepChanged(CurUninstallStep: TUninstallStep);
begin
  case CurUninstallStep of
    usUninstall:
      begin
        if MsgBox(ExpandConstant('{cm:DeleteSettings}'), mbConfirmation, MB_YESNO or MB_DEFBUTTON2) = IDYES then
          begin
             DelTree(ExpandConstant('{app}\{#SettingsFile}'), False, True, False);
          end
      end;
  end;
end;