Wrong attribute name in the message.

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@498647 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -221,7 +221,7 @@ public class War extends Jar {
             && needxmlfile
             && !isInUpdateMode()) {
             throw new BuildException("No WEB-INF/web.xml file was added.\n"
-                    + "If this is your intent, set needxml='false' ");
+                    + "If this is your intent, set needxmlfile='false' ");
         }
         addedWebXmlFile = null;
         super.cleanUp();