You have already entered your address and are maybe not even in the European Union. You entered your address already and you are still seeing a red banner requesting your address. :/
We identified a bug that was fixed in 2015 but after the fix, there will be publishers who will still see the banner. To get rid of that banner, click the link from the banner and go to your account settings. Then click "confirm" to confirm the address. After that, you should no longer see the banner.