alter visibility mode only if not normal panel

when the panel mode is autohide, the visibility mode has to be
altered when the controller is open, or the panel will go invisible
also when the mode is windowcancover is better to alter, or the panel may disappear
as well.

shell/panelconfigview.cpp

@@ -49,7 +49,7 @@ PanelConfigView::PanelConfigView(Plasma::Containment *containment, PanelView *pa
     connect(&m_deleteTimer, &QTimer::timeout, this, &PanelConfigView::deleteLater);
 
     m_visibilityMode = panelView->visibilityMode();
-    panelView->setVisibilityMode(PanelView::WindowsGoBelow);
+
     setScreen(panelView->screen());
     connect(panelView, &QWindow::screenChanged, this,
             [=](QScreen *screen) {
@@ -147,7 +147,10 @@ void PanelConfigView::showEvent(QShowEvent *ev)
     }
 
     m_deleteTimer.stop();
-    m_panelView->setVisibilityMode(PanelView::WindowsGoBelow);
+
+    if (m_visibilityMode != PanelView::NormalPanel) {
+        m_panelView->setVisibilityMode(PanelView::WindowsGoBelow);
+    }
     PanelShadows::self()->addWindow(this);
 }