footnoteList cannot be null there; instead we want to check if it's empty

git-svn-id: https://svn.apache.org/repos/asf/xmlgraphics/fop/trunk@1603726 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/fop/layoutmgr/list/ListItemLayoutManager.java

@@ -331,7 +331,7 @@ public class ListItemLayoutManager extends SpacedBorderedPaddedBlockLayoutManage
             addedBoxHeight += boxHeight;
             ListItemPosition stepPosition = new ListItemPosition(this,
                     start[0], end[0], start[1], end[1]);
-            if (footnoteList == null) {
+            if (footnoteList.isEmpty()) {
                 returnList.add(new KnuthBox(boxHeight, stepPosition, false));
             } else {
                 returnList.add(new KnuthBlockBox(boxHeight, footnoteList, stepPosition, false));