A federal appeals court has given opponents of the city of Chicago’s Airbnb ordinance another chance to challenge its constitutionality if they can prove they have standing to pursue litigation in the first place.A 7th U.S. Circuit Court of Appeals vacated rulings issued by U.S. District Judge Sara L. Ellis that effectively dismissed a complaint filed by home-sharing host advocacy group Keep Chicago Livable and six other homeowners, renters and visitors to Chicago.The suit contended its Shared Housing Ordinance …