Adding Apache Header to Test Directory

test/assets/www/htmlnotfound/error.html

@@ -1 +1,19 @@
-This is an error page.
+<!--
+         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.$
+-->
+This is an error page.