modules/auth: updated docbook version

modules/auth/auth.xml

@@ -1,5 +1,5 @@
 <?xml version='1.0'?>
-<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
+<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.4//EN"
   "http://www.oasis-open.org/docbook/xml/4.4/docbookx.dtd">
 
 <refentry id="module.auth"