fix javadoc comment

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@1586196 13f79535-47bb-0310-9956-ffa450edef68
adding mention of Java 1.9

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@1586198 13f79535-47bb-0310-9956-ffa450edef68