Law enforcement agents stayed within the Fourth Amendment’s boundaries — although they did step close to the line — when they used a garage-door opener seized during a traffic stop to locate a drug stash house, a federal appeals court held Monday.The 7th U.S. Circuit Court of Appeals affirmed U.S. District Judge Robert M. Dow Jr.’s denial of a motion to suppress the handgun, drugs and other evidence of trafficking found in the stash house.The motion was made by co-defendants Jason Correa, who was …