[gnome-boxes] Make submodule URL absolute

[Zeeshan Ali Khattak <zeeshanak src gnome org>]

commit 14ec4aa3c19f6cde4333026fe4cc734982ea7747
Author: Lasse Schuirmann <lasse schuirmann net>
Date:   Fri Apr 25 14:23:35 2014 +0200

    Make submodule URL absolute
    
    This makes life easier for people cloning from non-standard (not on
    git.gnome) repositories.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=728948

 .gitmodules |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/.gitmodules b/.gitmodules
index 303eb9b..bfd964e 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,3 +1,3 @@
 [submodule "libgd"]
        path = libgd
-       url = ../libgd
+       url = git://git.gnome.org/libgd