klighd: "Fixed" broken ChildArea Placement

See f613c17
This line was removed thinking it was not needed in #165, but in fact it
was needed. Reverting this to its working previous state.

plugins/de.cau.cs.kieler.klighd/src/de/cau/cs/kieler/klighd/internal/macrolayout/KlighdDiagramLayoutConnector.java

@@ -378,6 +378,10 @@ private void createNode(final LayoutMapping mapping, final KNode node,
 
         // KLighD is somewhat mean and doesn't care about existing insets
         node.setInsets(insets);
+        // This line should not be needed as it just sets the default paddings if none existed yet, and every use of
+        // this property needs to "get" it first, theoretically resulting in always setting the default values.
+        // But this still seems to be necessary to fix child area placement. See also f613c1758bdc05c4461e4a2cc47dee0cb8556416 
+        node.getProperty(CoreOptions.PADDING);
         // The Insets are used in {@link KlighdLayoutConfigurationStore} to retrieve the padding
         // of the node