If the main window has been minimized to the taskbar (iconified) calling "Show/Hide", "Send" or "Receive" actions from the tray icon menu has no effect: the main window still minimized.

It seems like a Qt bug similar to that old [one](https://bugreports.qt.io/browse/QTBUG-31117).

Tested platform: Linux Mint 19, Qt 5.9.5 / 5.9.6
unitDisplayControl->setOptionsModel(_clientModel->getOptionsModel());
        OptionsModel* optionsModel = _clientModel->getOptionsModel();
        if(optionsModel)
        {
            
            connect(optionsModel, &OptionsModel::hideTrayIconChanged, this, &BitcoinGUI::setTrayIconVisible);
            
            setTrayIconVisible(optionsModel->getHideTrayIcon());
        }
    } else {
        
        toggleHideAction->setEnabled(false);
        if(trayIconMenu)
        {
            
            trayIconMenu->clear();
        }
        
        rpcConsole->setClientModel(nullptr);
#ifdef ENABLE_WALLET
        if (walletFrame)
        {
            walletFrame->setClientModel(nullptr);
        }
#endif 
        unitDisplayControl->setOptionsModel(nullptr);
    }
}
#ifdef ENABLE_WALLET
bool BitcoinGUI::addWallet(WalletModel *walletModel)