message: rpc: Compile on GCC4.8
diff: // Copyright (c) 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.
  @@ -51,7 +51,7 @@ struct RPCCommandExecution
  explicit RPCCommandExecution(const std::string& method)
  {
  LOCK(g_rpc_server_info.mutex);
  - it = g_rpc_server_info.active_commands.insert(g_rpc_server_info.active_commands.cend(), {method, GetTimeMicros()});
  + it = g_rpc_server_info.active_commands.insert(g_rpc_server_info.active_commands.end(), {method, GetTimeMicros()});
  }
  ~RPCCommandExecution()
  {
  