Update docbook doctype declaration.

doc/en/index.docbook

@@ -1,14 +1,10 @@
 <?xml version="1.0" ?>
-<!DOCTYPE book PUBLIC "-//KDE//DTD DocBook XML V4.1.2-Based Variant V1.1//EN" "dtd/kdex.dtd" [
+<!DOCTYPE book PUBLIC "-//KDE//DTD DocBook XML V4.2-Based Variant V1.1//EN" "dtd/kdex.dtd" [
   <!ENTITY videopreview "<application>videopreview 0.1</application>">
   <!ENTITY kappname "&videopreview;"><!-- Do *not* replace kappname-->
   <!ENTITY package "kde-module"><!-- tdebase, tdeadmin, etc -->
   <!ENTITY % addindex "IGNORE">
   <!ENTITY % English "INCLUDE"><!-- change language only here -->
-  
-  
-  <!-- Do not define any other entities; instead, use the entities
-       from kde-genent.entities and $LANG/user.entities. -->
 ]>
 <!-- kdoctemplate v0.8 October 1 1999 
      Minor update to "Credits and Licenses" section on August 24, 2000