message: Fix a shadowing warning
  This was likely introduced by the change that was getting rid of the
  BOOST_FOREACHes.
diff: @@ -6281,9 +6281,9 @@ bool ProcessMessage(CNode *pfrom, std::string strCommand, CDataStream &vRecv, in
  // Download as much as possible, from earliest to latest.
  unsigned int nAskFor = 0;
  - for (auto i = vToFetch.rbegin(); i != vToFetch.rend(); i++)
  + for (auto pindex_iter = vToFetch.rbegin(); pindex_iter != vToFetch.rend(); pindex_iter++)
  {
  - CBlockIndex *pindex = *i;
  + CBlockIndex *pindex = *pindex_iter;
  // pindex must be nonnull because we populated vToFetch a few lines above
  CInv inv(MSG_BLOCK, pindex->GetBlockHash());
  if (!AlreadyHaveBlock(inv))
  