Flight attendants who maintain they lost income as a result of the grounding of Boeing’s 737 MAX aircraft do not have a case against the plane-manufacturing giant, a federal judge held.In a written opinion this week, U.S. District Judge Robert W. Gettleman threw out a proposed class-action lawsuit brought against The Boeing Co. by Southwest Airlines flight attendants.The suit accused Boeing of making material misrepresentations — to regulators, the public and its customers, including Southwest — in order …