The owner of a Queens pizzeria stabbed trying to thwart a robbery said he was “satisfied” with the 8-year sentence his attacker received Thursday and hoped the 19-year-old culprit would learn from his mistake. “It’s a fitting punishment for what happened, that’s totally understandable,” Louie Suljovic, 39, owner of Louie Pizzeria on Baxter Ave. at 82nd St. said. “I’m satisfied.” He and his .