A federal appeals court has cut the ground from under the feet of a Chicago man who contends the Illinois Constitution’s so-called “pension protection clause” unfairly advantages state employees over other residents.The 7th U.S. Circuit Court of Appeals on Friday declined to revive a lawsuit challenging Article 13, Section 5 of the Illinois Constitution.That clause says benefits under public-employee pensions “shall not be diminished or impaired.”In an unpublished order, a panel of the court …