The 7th U.S. Circuit Court of Appeals Thursday, ruling en banc, tossed out a Chicago-area man’s conviction for trying to rob a drug stash house that didn’t actually exist, saying a trial judge erred by not letting him argue to jurors that federal agents entrapped him. The 8-to-2 decision by the 7th U.S. District Court of Appeals is a victory for critics who say such stash-house stings — typically overseen by the Bureau of Alcohol, Tobacco, Firearms and Explosives — are fundamentally unfair …