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)

{
#ifndef Q_OS_MAC 
    if(clientModel && clientModel->getOptionsModel())
    {
        if(!clientModel->getOptionsModel()->getMinimizeOnClose())
        {
            
            rpcConsole->close();
            QApplication::quit();
        }
        else
        {
            QMainWindow::showMinimized();
            event->ignore();
        }
    }
#else
    QMainWindow::closeEvent(event);
#endif
}
void BitcoinGUI::showEvent(QShowEvent *event)