KonvergoWindow: mark fixed QML properties as constant to avoid warnings

Shouldn't have any other effect.

src/ui/KonvergoWindow.h

@@ -30,9 +30,9 @@ class KonvergoWindow : public QQuickWindow
   Q_PROPERTY(QString debugInfo MEMBER m_debugInfo NOTIFY debugInfoChanged)
   Q_PROPERTY(QString videoInfo MEMBER m_videoInfo NOTIFY debugInfoChanged)
   Q_PROPERTY(qreal webScale READ webScale NOTIFY webScaleChanged)
-  Q_PROPERTY(qreal webHeightMax READ webHeightMax)
+  Q_PROPERTY(qreal webHeightMax READ webHeightMax CONSTANT)
   Q_PROPERTY(qreal windowScale READ windowScale NOTIFY windowScaleChanged)
-  Q_PROPERTY(QSize windowMinSize READ windowMinSize)
+  Q_PROPERTY(QSize windowMinSize READ windowMinSize CONSTANT)
   Q_PROPERTY(bool alwaysOnTop READ isAlwaysOnTop WRITE setAlwaysOnTop)
   Q_PROPERTY(bool webDesktopMode MEMBER m_webDesktopMode NOTIFY webDesktopModeChanged)
   Q_PROPERTY(QString webUrl READ webUrl NOTIFY webUrlChanged)