By Daniel Trotta and Jonathan Stempel (Reuters) -Wayne LaPierre resigned as leader of the National Rifle Association on Friday, ending a long career that saw it became one of the most powerful lobbies in Washington, only to have its prestige tarnished by graft accusations and a bankruptcy filing. LaPierre, 74, chief executive since 1991, steps down just as New York state Attorney General Letitia James brings a corruption trial against the NRA, due to begin in state Supreme Court on Monday. James had been seeking LaPierre’s removal from office, but he is still among three individual defendants …