[gnome-builder] doap: add Günther Wagner as co-maintainer

[Christian Hergert <chergert src gnome org>]

commit 747314861aa9a8887ba7d30e35c70eb64a2d2797
Author: Christian Hergert <chergert redhat com>
Date:   Tue Nov 16 08:50:48 2021 -0800

    doap: add Günther Wagner as co-maintainer

 gnome-builder.doap | 8 ++++++++
 1 file changed, 8 insertions(+)
---
diff --git a/gnome-builder.doap b/gnome-builder.doap
index 869b9fc35..9a0508466 100644
--- a/gnome-builder.doap
+++ b/gnome-builder.doap
@@ -31,4 +31,12 @@
       <gnome:userid>slafargue</gnome:userid>
     </foaf:Person>
   </maintainer>
+
+  <maintainer>
+    <foaf:Person>
+      <foaf:name>Günther Wagner</foaf:name>
+      <foaf:mbox rdf:resource="mailto:info gunibert de" />
+      <gnome:userid>gwagner</gnome:userid>
+    </foaf:Person>
+  </maintainer>
 </Project>