[gnome-calendar] flatpak: use GitLab url

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 0e1404a11b9effb9572546244161a4dc1db53fde
Author: Georges Basile Stavracas Neto <georges stavracas gmail com>
Date:   Mon Nov 27 13:30:51 2017 +0000

    flatpak: use GitLab url

 org.gnome.Calendar.json | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/org.gnome.Calendar.json b/org.gnome.Calendar.json
index 3408804..527786f 100644
--- a/org.gnome.Calendar.json
+++ b/org.gnome.Calendar.json
@@ -113,7 +113,7 @@
             "sources": [
                 {
                     "type": "git",
-                    "url": "git://git.gnome.org/gnome-calendar"
+                    "url": "https://gitlab.gnome.org/GNOME/gnome-calendar.git";
                 }
             ]
         }