After reports that iOS 9 updates have disabled iPhone 6 and 6s devices that had third-party repairs done to their Touch ID sensors, law firms in the U.S. and U.K. are considering legal action against Apple, The Guardian reports. Users with iPhones that have been repaired by someone other than Apple or that have unrepaired damage have reported receiving an “Error 53” message when updating their device’s software, leaving the phone…