In my current game (Vanilla 1.6.1) my empire has grown to around 30% of the terrritory. I would like to change Civics but my advisor tells me it will take 2 turns. This is to just change 1 Civic. I've never seen anything other than 1 turn before. What is going on? If I wait long enough will it eventually go back to 1 turn? Would it help to build the Forbidden Palace?