make the preserveLastModified field private

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@277080 13f79535-47bb-0310-9956-ffa450edef68

src/main/org/apache/tools/ant/taskdefs/SignJar.java

@@ -66,7 +66,7 @@ public class SignJar extends Task {
     protected boolean verbose;
     protected boolean internalsf;
     protected boolean sectionsonly;
-    protected boolean preserveLastModified;
+    private   boolean preserveLastModified;
 
     /** The maximum amount of memory to use for Jar signer */
     private String maxMemory;