Rename test object ScSpreadsheetSettingsObj to ScSpreadsheetSettings.

Change-Id: Ia70cc82e0ee20571ad029590db735f932e5c7958
Reviewed-on: https://gerrit.libreoffice.org/51723Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Jens Carl <j.carl43@gmx.de>