A man shot in the back Sunday night in the city’s University District was treated at Erie County Medical Center for what Buffalo police called a non-life-threatening wound.Shakille Dothard was shot on Shirley Avenue at about 8:15 p.m. Sunday. He was treated at ECMC before he left the emergency room, a hospital official said.Northeast District police said two shell casings were recovered in a nearby driveway on Shirley Avenue.