Fix some things around privacy policy/notice handling

Cleans up after !1384 (merged)

• Fix typo that avoided accepting anything the user selected on the privacy notice

  • Accepting it
  • Downgrading when not accepting it
  • (accidental downgrade of everybody when they try to accept it because it changed) <- luckily, this hasn't happened yet :-)

• Extend the existing tests to actually check what they said

• Add more tests to check that people are not accidentally downgraded