Remove myself as maintainer

I got the following error message after trying to remove my maintainer
entry from the DOAP file:

> Must have at least one doap:maintainer property with a gnome:userid
> property

So I'm adding the previous maintainer.

README.md

@@ -21,11 +21,9 @@ This code is released under the MIT License, see the Copyright file.
 
 ## Security
 
-This is open-source software written by hobbyists, maintained by a single
-volunteer, badly tested, written in a memory-unsafe language and full of
-security bugs. It is foolish to use this software to process untrusted data.
-As such, we treat security issues like any other bug. Each security report
-we receive will be made public immediately and won't be prioritized.
+This project is unmaintained and has
+[known security issues](https://gitlab.gnome.org/GNOME/libxml2/-/issues/346).
+It is foolish to use this software to process untrusted data.
 
 ## Build instructions
 

libxml2.doap

@@ -26,8 +26,8 @@ CygWin, MacOS X, RISC Os, OS/2, QNX, MVS,
 
   <maintainer>
     <foaf:Person>
-      <foaf:name>Nick Wellnhofer</foaf:name>
-      <gnome:userid>nwellnhof</gnome:userid>
+      <foaf:name>Daniel Veillard</foaf:name>
+      <gnome:userid>veillard</gnome:userid>
     </foaf:Person>
   </maintainer>
 </Project>