Add missing header.
diff --git a/app/src/main/resources/struts.xml b/app/src/main/resources/struts.xml
index 0a8f5aa..8ab6f6a 100644
--- a/app/src/main/resources/struts.xml
+++ b/app/src/main/resources/struts.xml
@@ -1,4 +1,21 @@
<?xml version="1.0" encoding="UTF-8" ?>
+<!--
+ Licensed to the Apache Software Foundation (ASF) under one or more
+ contributor license agreements. 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. For additional information regarding
+ copyright in this work, please see the NOTICE file in the top level
+ directory of this distribution.
+-->
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.5//EN"
"http://struts.apache.org/dtds/struts-2.5.dtd">
