[gtk-doc] devhelp: disable outputing a bogus doctype

[Stefan Kost <stefkost src gnome org>]

commit 4717c15d4b829266a578e168c6e44826ab418282
Author: Stefan Sauer <ensonic users sf net>
Date:   Fri May 15 21:49:30 2015 +0200

    devhelp: disable outputing a bogus doctype
    
    This was outputing the 'book' toplevel for html, which does not exists.

 devhelp2.xsl |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/devhelp2.xsl b/devhelp2.xsl
index b441df7..f9c3d9a 100644
--- a/devhelp2.xsl
+++ b/devhelp2.xsl
@@ -21,6 +21,7 @@
       <xsl:with-param name="method" select="'xml'"/>
       <xsl:with-param name="indent" select="'yes'"/>
       <xsl:with-param name="encoding" select="'utf-8'"/>
+      <xsl:with-param name="doctype-public"/>
       <xsl:with-param name="content">
         <xsl:call-template name="devhelp2"/>
       </xsl:with-param>