After a rare sales miss, McDonald's (MCD) announced a shakeup of its U.S. leadership team. The world's largest burger chain said Jan Fields, president of McDonald's USA, will be replaced by Jeff Stratton, its global chief restaurant officer, effective Dec. 1. The company denied there was no connection between Fields' departure and the notice a week ago of the first monthly decline in sales in nine years. Sales at its U.S. restaurants open at least