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 (!walletFrame) return;
    if (!walletFrame->addWallet(walletModel)) return;
    const QString display_name = walletModel->getDisplayName();
    setWalletActionsEnabled(true);
    rpcConsole->addWallet(walletModel);
    m_wallet_selector->addItem(display_name, QVariant::fromValue(walletModel));
    if (m_wallet_selector->count() == 2) {
        m_wallet_selector_label_action->setVisible(true);
        m_wallet_selector_action->setVisible(true);
    }
}
void BitcoinGUI::removeWallet(WalletModel* walletModel)
{
    if (!walletFrame) return;
    int index = m_wallet_selector->findData(QVariant::fromValue(walletModel));
    m_wallet_selector->removeItem(index);
    if (m_wallet_selector->count() == 0) {
        setWalletActionsEnabled(false);
    } else if (m_wallet_selector->count() == 1) {
        m_wallet_selector_label_action->setVisible(false);
        m_wallet_selector_action->setVisible(false);
    }
    rpcConsole->removeWallet(walletModel);
    walletFrame->removeWallet(walletModel);
    updateWindowTitle();
}
void BitcoinGUI::setCurrentWallet(WalletModel* wallet_model)