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)

if(curStyle == "QWindowsStyle" || curStyle == "QWindowsXPStyle")
    {
        progressBar->setStyleSheet("QProgressBar { background-color: #e8e8e8; border: 1px solid grey; border-radius: 7px; padding: 1px; text-align: center; } QProgressBar::chunk { background: QLinearGradient(x1: 0, y1: 0, x2: 1, y2: 0, stop: 0 #FF8000, stop: 1 orange); border-radius: 7px; margin: 0px; }");
    }
    statusBar()->addWidget(progressBarLabel);
    statusBar()->addWidget(progressBar);
    statusBar()->addPermanentWidget(frameBlocks);
    
    this->installEventFilter(this);
    
    setWalletActionsEnabled(false);
    
    subscribeToCoreSignals();
    connect(connectionsControl, &GUIUtil::ClickableLabel::clicked, [this] {
        m_node.setNetworkActive(!m_node.getNetworkActive());
    });
    connect(labelProxyIcon, &GUIUtil::ClickableLabel::clicked, [this] {
        openOptionsDialogWithTab(OptionsDialog::TAB_NETWORK);
    });
    modalOverlay = new ModalOverlay(enableWallet, this->centralWidget());
    connect(labelBlocksIcon, &GUIUtil::ClickableLabel::clicked, this, &BitcoinGUI::showModalOverlay);
    connect(progressBar, &GUIUtil::ClickableProgressBar::clicked, this, &BitcoinGUI::showModalOverlay);
#ifdef ENABLE_WALLET
    if(enableWallet) {
        connect(walletFrame, &WalletFrame::requestedSyncWarningInfo, this, &BitcoinGUI::showModalOverlay);
    }
#endif
#ifdef Q_OS_MAC
    m_app_nap_inhibitor = new CAppNapInhibitor;
#endif