put the correct default value into comments

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@348912 13f79535-47bb-0310-9956-ffa450edef68

src/main/org/apache/tools/ant/filters/util/ChainReaderHelper.java

@@ -86,7 +86,7 @@ public final class ChainReaderHelper {
     }
 
     /**
-     * Sets the buffer size to be used.  Defaults to 4096,
+     * Sets the buffer size to be used.  Defaults to 8192,
      * if this method is not invoked.
      * @param size the buffer size to use
      */