[gnome-control-center/gnome-3-26] Update submodule URLs to current GitLab URLs

[Debarshi Ray <debarshir src gnome org>]

commit 77f7c250b8f574aaa0216b45d892d416d6ba0012
Author: Debarshi Ray <debarshir gnome org>
Date:   Thu Oct 4 13:18:51 2018 +0200

    Update submodule URLs to current GitLab URLs

 .gitmodules | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/.gitmodules b/.gitmodules
index f096bd7f7..6d0248a2a 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,7 +1,7 @@
 [submodule "panels/sound/gvc"]
        path = panels/sound/gvc
-       url = git://git.gnome.org/libgnome-volume-control
+       url = https://gitlab.gnome.org/GNOME/libgnome-volume-control.git
 
 [submodule "libgd"]
        path = libgd
-       url = git://git.gnome.org/libgd
+       url = https://gitlab.gnome.org/GNOME/libgd.git