tor/changes/trove-2018-004

  o Minor bugfixes (denial-of-service):
    - Fix a possible crash on malformed consensus. If a consensus had
      contained an unparseable protocol line, it could have made clients
      and relays crash with a null-pointer exception. To exploit this
      issue, however, an attacker would need to be able to subvert the
      directory-authority system. Fixes bug 25251; bugfix on
      0.2.9.4-alpha. Also tracked as TROVE-2018-004.