[gnome-shell] submodules: Replace non-functional git.gnome.org URL by GNOME Gitlab URL

[Andre Klapper <aklapper src gnome org>]

commit fb39cc59523e6ede00f6ce814782bf34a0260a1c
Author: Andre Klapper <a9016009 gmx de>
Date:   Tue Sep 25 08:41:30 2018 +0200

    submodules: Replace non-functional git.gnome.org URL by GNOME Gitlab URL
    
    Fixes #606

 .gitmodules | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/.gitmodules b/.gitmodules
index f25d09d19..5ab4a386d 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,3 +1,3 @@
 [submodule "subprojects/gvc"]
        path = subprojects/gvc
-       url = https://git.gnome.org/browse/libgnome-volume-control
+       url = https://gitlab.gnome.org/GNOME/libgnome-volume-control.git