### Describe the issue
Warning messages are not displayed when running bitcoin-qt 0.14.2 and 0.14.99 with -disablewallet.
It might be better to always display them.

E.g. on MainNet the "This is a pre-release test build - use at your own risk - do not use for mining or merchant applications" is lost
![image](https://user-images.githubusercontent.com/3296421/29109760-853e5394-7ce4-11e7-8f05-bfcd66ada471.png)
![image](https://user-images.githubusercontent.com/3296421/29109806-adf6e67a-7ce4-11e7-8564-8883c44656ad.png)

On TestNet also the "Warning: unknown new rules activated (versionbit 28)" is missed
![image](https://user-images.githubusercontent.com/3296421/29110269-6b24b79e-7ce6-11e7-91e7-823227eaa200.png)
![image](https://user-images.githubusercontent.com/3296421/29110035-9142cf34-7ce5-11e7-8faf-264e805cdaf4.png)

if (index.data(TransactionTableModel::WatchonlyRole).toBool())
        {
            QIcon iconWatchonly = qvariant_cast<QIcon>(index.data(TransactionTableModel::WatchonlyDecorationRole));
            QRect watchonlyRect(boundingRect.right() + 5, mainRect.top()+ypad+halfheight, 16, halfheight);
            iconWatchonly.paint(painter, watchonlyRect);
        }
        if(amount < 0)
        {
            foreground = COLOR_NEGATIVE;
        }
        else if(!confirmed)
        {
            foreground = COLOR_UNCONFIRMED;
        }
        else
        {
            foreground = option.palette.color(QPalette::Text);
        }
        painter->setPen(foreground);
        QString amountText = BitcoinUnits::formatWithUnit(unit, amount, true, BitcoinUnits::separatorAlways);
        if(!confirmed)
        {
            amountText = QString("[") + amountText + QString("]");
        }
        painter->drawText(amountRect, Qt::AlignRight|Qt::AlignVCenter, amountText);
        painter->setPen(option.palette.color(QPalette::Text));
        painter->drawText(amountRect, Qt::AlignLeft|Qt::AlignVCenter, GUIUtil::dateTimeStr(date));
        painter->restore();
    }
    inline QSize sizeHint(const QStyleOptionViewItem &option, const QModelIndex &index) const