(Reuters) -The man accused of killing 10 Black people at a western New York grocery store pleaded not guilty to 27 hate crime and firearms charges stemming from the Buffalo shooting massacre, a court spokesperson said on Monday. The accused gunman, Payton Gendron, 19, appeared briefly in the Buffalo courtroom of U.S. Magistrate Judge Kenneth Schroeder Monday morning. He is charged with 14 hate crimes violations and 13 firearms offenses. Prosecutors have 45 days to turn over discovery to the defendant’s attorneys, Barbara Burns, a U.S. Department of Justice public information officer, told Reut…