Update DirectionalLightShadowRenderer: remove unused imports

Author: capdevon

jme3-core/src/main/java/com/jme3/shadow/DirectionalLightShadowRenderer.java

@@ -44,7 +44,6 @@
 import com.jme3.renderer.Camera;
 import com.jme3.renderer.queue.GeometryList;
 import com.jme3.renderer.queue.RenderQueue;
-import com.jme3.scene.Node;
 import com.jme3.scene.Spatial;
 import com.jme3.util.clone.Cloner;