[gnome-shell] git: Always use libgnome-volume-control submodule from GNOME group

[Marge Bot <marge-bot src gnome org>]

commit 1c7eb13caf5a857c524a5204fbe5c9307a9abe9c
Author: Sebastian Keller <skeller gnome org>
Date:   Thu Aug 4 18:31:16 2022 +0200

    git: Always use libgnome-volume-control submodule from GNOME group
    
    Otherwise CI will fail for anyone who does not have a fork of it in
    their personal projects.
    
    Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/2403>

 .gitmodules | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/.gitmodules b/.gitmodules
index aa33bbb911..bb57dfc6c6 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,3 +1,3 @@
 [submodule "subprojects/gvc"]
        path = subprojects/gvc
-       url = ../libgnome-volume-control.git
+       url = ../../GNOME/libgnome-volume-control.git