[gupnp] doc: Also set URL to docbook 4.5

[Jens Georg <jensgeorg src gnome org>]

commit 7a7760516ac295eb0bd92b11d28dea417c75561a
Author: Jens Georg <mail jensge org>
Date:   Sat Sep 3 10:40:27 2022 +0200

    doc: Also set URL to docbook 4.5
    
    Even if we render the manpage with nonet, should be consistent

 doc/gupnp-binding-tool.xml.in | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/doc/gupnp-binding-tool.xml.in b/doc/gupnp-binding-tool.xml.in
index e71fdec..2ec6904 100644
--- a/doc/gupnp-binding-tool.xml.in
+++ b/doc/gupnp-binding-tool.xml.in
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN" 
"http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd";>
+<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN" 
"http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd";>
 
 <refentry id="gupnp-binding-tool" xmlns:xi="http://www.w3.org/2003/XInclude";>
   <refmeta>