Add missing licence header

git-svn-id: https://svn.apache.org/repos/asf/sling/trunk@1676329 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/src/main/webapp/WEB-INF/web.xml b/src/main/webapp/WEB-INF/web.xml
index dda85cd..97ea881 100644
--- a/src/main/webapp/WEB-INF/web.xml
+++ b/src/main/webapp/WEB-INF/web.xml
@@ -1,4 +1,22 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+    Licensed to the Apache Software Foundation (ASF) under one
+    or more contributor license agreements.  See the NOTICE file
+    distributed with this work for additional information
+    regarding copyright ownership.  The ASF licenses this file
+    to you under the Apache License, Version 2.0 (the
+    "License"); you may not use this file except in compliance
+    with the License.  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+    Unless required by applicable law or agreed to in writing,
+    software distributed under the License is distributed on an
+    "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+    KIND, either express or implied.  See the License for the
+    specific language governing permissions and limitations
+    under the License.
+-->
 <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee"
     xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
 	xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"