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.
{
    QString strTitle = tr("Bitcoin"); 
    
    int nMBoxIcon = QMessageBox::Information;
    int nNotifyIcon = Notificator::Information;
    QString msgType;
    
    if (!title.isEmpty()) {
        msgType = title;
    }
    else {
        switch (style) {
        case CClientUIInterface::MSG_ERROR:
            msgType = tr("Error");
            break;
        case CClientUIInterface::MSG_WARNING:
            msgType = tr("Warning");
            break;
        case CClientUIInterface::MSG_INFORMATION:
            msgType = tr("Information");
            break;
        default:
            break;
        }