MAINTAINERS: update libvirt devel mailing list address

Effective immediately, the libvirt project has moved its list off
libvir-list@redhat.com, to devel@lists.libvirt.org

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
diff --git a/MAINTAINERS b/MAINTAINERS
index b86ea7f..751860e 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -4062,7 +4062,7 @@
 F: contrib/gitdm/*
 
 Incompatible changes
-R: libvir-list@redhat.com
+R: devel@lists.libvirt.org
 F: docs/about/deprecated.rst
 
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