Federal law says states must allow their citizens to apply for absentee ballots if they are eligible voters living abroad.But that flexibility doesn’t extend to U.S. territories such as Puerto Rico or Guam — at least if you’re a former Illinois resident.A federal appeals court earlier this year ruled a handful of former Illinois residents didn’t have a case against the federal overseas voting law, writing that it’s up to the states to decide if those territories can get absentee ballots.Now …