message: remove usage of boost::bind
  boost::bind usage was removed in However a new usage snuck in as
  part of
diff: @@ -426,7 +426,7 @@ void WalletModel::subscribeToCoreSignals()
  m_handler_transaction_changed = m_wallet->handleTransactionChanged(std::bind(NotifyTransactionChanged, this, std::placeholders::_1, std::placeholders::_2));
  m_handler_show_progress = m_wallet->handleShowProgress(std::bind(ShowProgress, this, std::placeholders::_1, std::placeholders::_2));
  m_handler_watch_only_changed = m_wallet->handleWatchOnlyChanged(std::bind(NotifyWatchonlyChanged, this, std::placeholders::_1));
  - m_handler_can_get_addrs_changed = m_wallet->handleCanGetAddressesChanged(boost::bind(NotifyCanGetAddressesChanged, this));
  + m_handler_can_get_addrs_changed = m_wallet->handleCanGetAddressesChanged(std::bind(NotifyCanGetAddressesChanged, this));
  }
  void WalletModel::unsubscribeFromCoreSignals()
  