Fix signal/slot syntax

when using the string based connection syntax we have to follow a
specific way of writing things. The current implementation is off.

shell/panelview.cpp

@@ -1212,10 +1212,10 @@ void PanelView::handleQmlStatusChange(QQmlComponent::Status status)
                    this, &PanelView::handleQmlStatusChange);
 
         updatePadding();
-        connect(rootObject, SIGNAL(bottomPaddingChanged()), this, SLOT(PanelView::updatePadding));
-        connect(rootObject, SIGNAL(topPaddingChanged()), this, SLOT(PanelView::updatePadding));
-        connect(rootObject, SIGNAL(rightPaddingChanged()), this, SLOT(PanelView::updatePadding));
-        connect(rootObject, SIGNAL(leftPaddingChanged()), this, SLOT(PanelView::updatePadding));
+        connect(rootObject, SIGNAL(bottomPaddingChanged()), this, SLOT(updatePadding()));
+        connect(rootObject, SIGNAL(topPaddingChanged()), this, SLOT(updatePadding()));
+        connect(rootObject, SIGNAL(rightPaddingChanged()), this, SLOT(updatePadding()));
+        connect(rootObject, SIGNAL(leftPaddingChanged()), this, SLOT(updatePadding()));
 
         const QVariant maskProperty = rootObject->property("panelMask");
         if (static_cast<QMetaType::Type>(maskProperty.type()) == QMetaType::QRegion) {