One of Boeing’s most important assembly lines took another hit from abroad Monday. Germany said it would buy 35 Lockheed Martin F-35 fighter jets and use upgraded European-made fighters to do jobs it once reserved for Boeing F/A-18 Super Hornets. Boeing had banked on German orders of Super Hornets and Growlers, their electronic warfare variants, to keep busy thousands of workers north of Lambert Field and across the country. “It feels like the market for the Super Hornet is gradually eroding,” said Loren Thompson, a longtime defense industry consultant and executive with the Lexington Institut…