SEATTLE — Facing severe criticism after a door plug blew out on a 737 Max over Oregon this month, Boeing said Monday that it is withdrawing a request for a safety exemption needed to certify a new model of the plane.The company asked federal regulators late last year to allow it to begin delivering its 737 Max 7 airliner to customers even though it does not meet a safety standard designed to prevent part of the engine housing from overheating and breaking off during flight.But after a door panel blew out on ...