fix javadoc comment

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

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

@@ -212,7 +212,7 @@ public final class JavaEnvUtils {
      * only one hit: a new constant in the class SourceVersion.
      * So we have to check that ...
      * 
-     * @throws An exception if we can't load the class or don't find the new constant.
+     * @throws Exception if we can't load the class or don't find the new constant.
      *    This is the behavior when searching for new features on older versions.
      * @since Ant 1.9.4
      */