BOSCAWEN, N.H. — A New Hampshire prep school graduate convicted of sexually assaulting a 15-year-old classmate reported to jail Wednesday to begin serving the remaining 10 months of his jail sentence. Labrie, of Tunbridge, Vermont, was acquitted in 2015 of raping a 15-year-old classmate Chessy Prout as part of “Senior Salute,” a game of sexual conquest, at St. Paul’s School. …