The part of the GUI that this setting is relevant for does not exist in a `--disable-wallet` build. 

![wallet_prefs](https://user-images.githubusercontent.com/863730/70331435-72547300-180d-11ea-842d-82f8529ae982.png)
{
    delete ui;
}
void OptionsDialog::setModel(OptionsModel *_model)
{
    this->model = _model;
    if(_model)
    {
        
        if (_model->isRestartRequired())
            showRestartWarning(true);
        
        static constexpr uint64_t nMinDiskSpace = (MIN_DISK_SPACE_FOR_BLOCK_FILES / GB_BYTES) + (MIN_DISK_SPACE_FOR_BLOCK_FILES % GB_BYTES) ? 1 : 0;
        ui->pruneSize->setRange(nMinDiskSpace, std::numeric_limits<int>::max());
        QString strLabel = _model->getOverriddenByCommandLine();
        if (strLabel.isEmpty())
            strLabel = tr("none");
        ui->overriddenByCommandLineLabel->setText(strLabel);
        mapper->setModel(_model);
        setMapper();
        mapper->toFirst();
        updateDefaultProxyNets();
    }