SPRINGFIELD — Flanked by consumer debt advocates, Gov. J.B. Pritzker on Monday signed the Consumer Fairness Act into law at the Chicago Volunteer Legal Services’ Loop offices.The new law — which takes effect Jan. 1 — reduces the post-judgment interest rate on consumer debt to 5% from 9%, and the window of opportunity for a debt collector to enforce a judgment shrinks from 26 years to 17 years.&ldquo …