Fix Build Regression due to faulty import.

jme3-assetpack-support/src/com/jme3/gde/assetpack/browser/properties/SelectionPropertyEditor.java

@@ -38,7 +38,8 @@ import java.beans.PropertyChangeEvent;
 import java.beans.PropertyChangeListener;
 import java.beans.PropertyEditor;
 import java.util.Iterator;
-import java.util.LinkedList;
+import java.util.ArrayList;
+import java.util.List;
 
 /**
  *