The 50-year prison sentence a man received for a murder he committed when he was 15 years old was vacated by a state appeals panel Monday in light of legislative changes made to the state’s automatic transfer provision.When Sebastian Rodriguez was arrested and charged with the Oct. 1, 2008, murder of 13-year-old Sameere Conn, he was automatically transferred from juvenile court to criminal court for his trial.Under Illinois law at the time, 15-year-olds charged with first-degree murder fell under the state’s …