  o Removed features (network parameters):
     - The "optimistic data" feature is now always on; there is no longer an
       option to disable it from the torrc file or from the consensus
       directory.
       Closes part of 40139.
     - The "usecreatefast" network parameter is now removed; there is no
       longer an option for authorities to turn it off. Closes part of 40139.
