#3533 / afterSave: sqlUpdate auf child-record ändert xId von Hauptrecord auf 0
After 'sqlUpdate' a 'sqlDelete' have been always fired, even it was empty. After firing 'sqlDelete' the current 'slaveId' has been set to '0'. Thad 'id' has been written to the primary record. Now, 'sqlDelete' will be only fired if there is a sqlDelete is given and non empty.