There is no such box. Hence the problem. Unless it's somewhere hiding. Because I had that box checked before the move. And looked for it again. Nothing.
1. Log out
2. look at the top left hand corner of the page at "Welcome, Guest. Please login or register." and click on "login"
3. Look at the bottom box above the "login" button. It should be a small square box that says "Always stay logged in:" click on the box
4. Press the login button at the bottom
5. profit