### 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)

QWidget(parent),
    ui(new Ui::OverviewPage),
    clientModel(0),
    walletModel(0),
    txdelegate(new TxViewDelegate(platformStyle, this))
{
    ui->setupUi(this);
    m_balances.balance = -1;
    
    QIcon icon = platformStyle->SingleColorIcon(":/icons/warning");
    icon.addPixmap(icon.pixmap(QSize(64,64), QIcon::Normal), QIcon::Disabled); 
    ui->labelTransactionsStatus->setIcon(icon);
    ui->labelWalletStatus->setIcon(icon);
    
    ui->listTransactions->setItemDelegate(txdelegate);
    ui->listTransactions->setIconSize(QSize(DECORATION_SIZE, DECORATION_SIZE));
    ui->listTransactions->setMinimumHeight(NUM_ITEMS * (DECORATION_SIZE + 2));
    ui->listTransactions->setAttribute(Qt::WA_MacShowFocusRect, false);
    connect(ui->listTransactions, &QListView::clicked, this, &OverviewPage::handleTransactionClicked);
    
    showOutOfSyncWarning(true);
    connect(ui->labelWalletStatus, &QPushButton::clicked, this, &OverviewPage::handleOutOfSyncWarningClicks);
    connect(ui->labelTransactionsStatus, &QPushButton::clicked, this, &OverviewPage::handleOutOfSyncWarningClicks);
}
void OverviewPage::handleTransactionClicked(const QModelIndex &index)