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
{
    overviewAction->setEnabled(enabled);
    sendCoinsAction->setEnabled(enabled);
    sendCoinsMenuAction->setEnabled(enabled);
    receiveCoinsAction->setEnabled(enabled);
    receiveCoinsMenuAction->setEnabled(enabled);
    historyAction->setEnabled(enabled);
    encryptWalletAction->setEnabled(enabled);
    backupWalletAction->setEnabled(enabled);
    changePassphraseAction->setEnabled(enabled);
    signMessageAction->setEnabled(enabled);
    verifyMessageAction->setEnabled(enabled);
    usedSendingAddressesAction->setEnabled(enabled);
    usedReceivingAddressesAction->setEnabled(enabled);
    openAction->setEnabled(enabled);
}
void BitcoinGUI::createTrayIcon(const NetworkStyle *networkStyle)
{
    assert(QSystemTrayIcon::isSystemTrayAvailable());
#ifndef Q_OS_MAC
    trayIcon = new QSystemTrayIcon(this);
    QString toolTip = tr("%1 client").arg(tr(PACKAGE_NAME)) + " " + networkStyle->getTitleAddText();
    trayIcon->setToolTip(toolTip);
    trayIcon->setIcon(networkStyle->getTrayAndWindowIcon());
    trayIcon->hide();
#endif
    notificator = new Notificator(QApplication::applicationName(), trayIcon, this);
}
void BitcoinGUI::createTrayIconMenu()