Freeport LNG, the second-biggest U.S. liquefied natural gas (LNG) exporter, got approval from federal regulators on Thursday to take early steps to restart its fire-idled LNG export plant in Texas.Freeport, however, has not yet sought permission to restart the liquefaction trains that turn natural gas into LNG for export. That resumption of LNG production will have to come in a later request with federal regulators.Energy analysts have said they still expect most of the plant's…