o Deprecated features:
    - As we are not recommending 0.2.5 anymore we require relays that once had
      an ed25519 key associated with their RSA key to always have that key
      instead of allowing them to drop back to a version that didn't support
      ed25519. This means they need to use a new RSA key if the want to
      downgrade to an older version of tor without ed25519. Closes ticket 20522.