WW-1677 <s:submit type="button" does not render the enclosed content inside properly

${parameters.body} is not only the body of the tag but also the html opening of the tag, so it cannot be escaped

git-svn-id: https://svn.apache.org/repos/asf/struts/struts2/trunk@681101 13f79535-47bb-0310-9956-ffa450edef68

core/src/main/java/org/apache/struts2/views/jsp/ui/SubmitTag.java

@@ -32,7 +32,7 @@ import com.opensymphony.xwork2.util.ValueStack;
 /**
  * @see Submit
  */
-public class SubmitTag extends AbstractUITag {
+public class SubmitTag extends AbstractClosingTag {
 
     private static final long serialVersionUID = 2179281109958301343L;