Avoid artifacts with background colors not being cleared

Issue-Ref: 4123
Issue-Url: af3#4123



Signed-off-by: Simon Barner <barner@fortiss.org>

org.fortiss.tooling.common.ui/src/org/fortiss/tooling/common/ui/javafx/control/treetableview/.ratings

@@ -8,7 +8,7 @@ DynamicTreeItemBase.java d883066ecc181120302ca32f328538de7a45b093 GREEN
 DynamicTreeTableUIProviderBase.java a4cd60795d114984f7fd255f273fc39937889f22 GREEN
 DynamicTreeTableViewer.java ead6f6671e9cb6b14632940bf440cba7e81fcd98 GREEN
 DynamicTreeUIProviderBase.java 82d3c051213f0147f4c67ad247a08696cee73110 GREEN
-DynamicTreeViewer.java fb584441c40c8e9f7cbdece9eb10eb50e61bbae8 YELLOW
+DynamicTreeViewer.java 545f1ca10b7b3cad171b294a4b447875da45c9ed YELLOW
 DynamicTreeViewerBase.java a2013538b62d86f6a09efdf2cd78babac2072484 GREEN
 EmptyChildrenContentProvider.java 51b4468f9df8423abeea5ac6aa2f6cf99c2eb512 GREEN
 IDoubleClickHandler.java 447f7769dead9a106b3ea3139ef0da51eb0b9a89 GREEN

org.fortiss.tooling.common.ui/src/org/fortiss/tooling/common/ui/javafx/control/treetableview/DynamicTreeViewer.java

@@ -173,6 +173,7 @@ public final class DynamicTreeViewer<T> extends DynamicTreeViewerBase<T> {
 					} else {
 						this.setText(null);
 						this.setGraphic(null);
+						this.setStyle(null);
 					}
 					this.setContextMenu(menu);
 				}