-sorry prevent NullPointerException

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@518897 13f79535-47bb-0310-9956-ffa450edef68

src/main/org/apache/tools/ant/util/FileUtils.java

@@ -1303,6 +1303,9 @@ public class FileUtils {
 
     
     private static void closeQuietly(Object o) {
+        if (null == o) {
+            return;
+        }
         try {
             if(ReflectUtil.respondsTo(o, "close")) {
                 ReflectUtil.invoke(o, "close");