Fix typo in xml file

git-svn-id: http://www.varnish-cache.org/svn/branches/2.0@4019 d4fa192b-c00b-0410-8231-f00ffab90ce4

doc/changes-2.0.3-2.0.4.xml

@@ -81,6 +81,7 @@
       full length, but stopped at the first NULL byte.  We no longer
       do that, enabling ESI processing of binary data.</para>
     </change>
+  </subsystem>
 
   <subsystem>
     <name>varnishtest</name>