debian: Update references to ubuntu fork

debian/control

@@ -1,7 +1,8 @@
 Source: gnome-shell-extensions
 Section: gnome
 Priority: optional
-Maintainer: Debian GNOME Maintainers <pkg-gnome-maintainers@lists.alioth.debian.org>
+Maintainer: Ubuntu Developers <ubuntu-devel-discuss@lists.ubuntu.com>
+XSBC-Original-Maintainer: Debian GNOME Maintainers <pkg-gnome-maintainers@lists.alioth.debian.org>
 Uploaders: Iain Lane <laney@debian.org>, Jeremy Bícha <jbicha@ubuntu.com>, Laurent Bigonville <bigon@debian.org>, Marco Trevisan (Treviño) <marco@ubuntu.com>
 Build-Depends: debhelper-compat (= 13),
                dh-sequence-gnome,
@@ -10,8 +11,10 @@ Build-Depends: debhelper-compat (= 13),
                meson (>= 1.1.0),
                sassc
 Standards-Version: 4.7.0
-Vcs-Browser: https://salsa.debian.org/gnome-team/gnome-shell-extensions
-Vcs-Git: https://salsa.debian.org/gnome-team/gnome-shell-extensions.git
+XS-Debian-Vcs-Browser: https://salsa.debian.org/gnome-team/gnome-shell-extensions
+XS-Debian-Vcs-Git: https://salsa.debian.org/gnome-team/gnome-shell-extensions.git
+Vcs-Browser: https://salsa.debian.org/gnome-team/gnome-shell-extensions/tree/ubuntu/latest
+Vcs-Git: https://salsa.debian.org/gnome-team/gnome-shell-extensions.git -b ubuntu/latest
 Homepage: https://wiki.gnome.org/Projects/GnomeShell/Extensions
 
 Package: gnome-shell-extensions

debian/gbp.conf

@@ -1,6 +1,7 @@
 [DEFAULT]
 pristine-tar = True
-debian-branch = debian/latest
+debian-branch = ubuntu/latest
+debian-tag=ubuntu/%(version)s
 upstream-branch = upstream/latest
 
 [buildpackage]