message: wallet: Remove unused import checkpoints.h
diff: // Copyright (c) 2009-2010 Satoshi Nakamoto
  -// Copyright (c) 2009-2018 The Bitcoin Core developers
  +// Copyright (c) 2009-2019 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 <wallet/wallet.h>
  #include <chain.h>
  -#include <checkpoints.h>
  #include <consensus/consensus.h>
  #include <consensus/validation.h>
  #include <fs.h>
  