Align geowebcache.xml schema namespace to 2.0.0

Author: petersmythe

geowebcache/core/src/main/resources/geowebcache.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <gwcConfiguration xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-  xmlns="http://geowebcache.org/schema/1.28.0"
-  xsi:schemaLocation="http://geowebcache.org/schema/1.28.0 http://geowebcache.org/schema/1.28.0/geowebcache.xsd">
+  xmlns="http://geowebcache.org/schema/2.0.0"
+  xsi:schemaLocation="http://geowebcache.org/schema/2.0.0 http://geowebcache.org/schema/2.0.0/geowebcache.xsd">
   <version>1.8.0</version>
   <backendTimeout>120</backendTimeout>
   <!-- Seeder thread pool configuration (optional, can be overridden by