Compile master, and run with `src/qt/bitcoin-qt -regtest -nowallet`. As expected, no icon is displayed. Load and unload a wallet. The `HD` icon remains.

On startup:
![on_startup](https://user-images.githubusercontent.com/863730/72410834-711b4c00-37a4-11ea-9a10-bfcf3db7ce68.png)

After a wallet load and unload:
![after_load_unload](https://user-images.githubusercontent.com/863730/72410838-737da600-37a4-11ea-8854-dd13301c0135.png)

#endif 
        unitDisplayControl->setOptionsModel(_clientModel->getOptionsModel());
        OptionsModel* optionsModel = _clientModel->getOptionsModel();
        if (optionsModel && trayIcon) {
            
            connect(optionsModel, &OptionsModel::hideTrayIconChanged, this, &BitcoinGUI::setTrayIconVisible);
            
            setTrayIconVisible(optionsModel->getHideTrayIcon());
        }
    } else {
        
        toggleHideAction->setEnabled(false);
        if(trayIconMenu)
        {
            
            trayIconMenu->clear();
        }
        
        rpcConsole->setClientModel(nullptr);
#ifdef ENABLE_WALLET
        if (walletFrame)
        {
            walletFrame->setClientModel(nullptr);
        }
#endif 
        unitDisplayControl->setOptionsModel(nullptr);
    }
}
#ifdef ENABLE_WALLET
void BitcoinGUI::setWalletController(WalletController* wallet_controller)