Noticed this while reviewing #13529, but it's also in master @ 5ba77df15. On macOS 10.13.6:

```
bitcoin-qt -disablewallet
```

<img width="1354" alt="schermafbeelding 2018-08-01 om 16 03 41" src="https://user-images.githubusercontent.com/10217/43526506-b23264d8-95a4-11e8-81a0-5debcad838ae.png">

The usual progress modal doesn't appear when QT starts, and clicking on the progress bar has no effect. It works fine when there's a wallet present.
{
    if(!clientModel)
        return;
    HelpMessageDialog dlg(m_node, this, true);
    dlg.exec();
}
void BitcoinGUI::showDebugWindow()
{
    GUIUtil::bringToFront(rpcConsole);
}
void BitcoinGUI::showDebugWindowActivateConsole()
{
    rpcConsole->setTabFocus(RPCConsole::TAB_CONSOLE);
    showDebugWindow();
}
void BitcoinGUI::showHelpMessageClicked()
{
    helpMessageDialog->show();
}
#ifdef ENABLE_WALLET
void BitcoinGUI::openClicked()
{
    OpenURIDialog dlg(this);
    if(dlg.exec())
    {
        Q_EMIT receivedURI(dlg.getURI());
    }
}
void BitcoinGUI::gotoOverviewPage()