message: test: Add missing include
diff: -// Copyright (c) 2011-2020 The Bitcoin Core developers
  +// Copyright (c) 2011-2021 The Bitcoin Core developers
  // Distributed under the MIT software license, see the accompanying
  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  #include <util/system.h>
  #include <util/time.h>
  #include <validation.h>
  +#include <versionbits.h>
  #include <test/util/setup_common.h>
  