SPRINGFIELD — When a state appellate court ruled that a property tax-exemption law was unconstitutional, the panel lacked jurisdiction to do so, the state Supreme Court decided in an opinion released today.In its unanimous opinion, the Illinois Supreme Court reversed a 4th District Appellate Court decision that found the tax law violates the state constitution’s revenue article.But the high court chose not to weigh in on whether the property tax law is constitutional, instead remanding the case back to the …