[gnome-control-center] CI: build flatpak using the "official" Docker image

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

commit 0f6a97eae1e5338809647d066fc8da7981308d10
Author: Claudio André <claudioandre br gmail com>
Date:   Sun Jul 15 18:26:00 2018 -0300

    CI: build flatpak using the "official" Docker image
    
    [skip ci]

 .gitlab-ci.yml                            | 2 +-
 build-aux/flatpak/org.gnome.Settings.json | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index ad49639e3..b9567f165 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -132,7 +132,7 @@ pages:
 ##
 flatpak:
   stage: deploy
-  image: claudioandre/settings:fedora.flatpak
+  image: registry.gitlab.gnome.org/gnome/gnome-nightly-oci/nightly:master
   artifacts:
     name: package
     paths:
diff --git a/build-aux/flatpak/org.gnome.Settings.json b/build-aux/flatpak/org.gnome.Settings.json
index e01d66792..1fde63fbf 100644
--- a/build-aux/flatpak/org.gnome.Settings.json
+++ b/build-aux/flatpak/org.gnome.Settings.json
@@ -1,7 +1,7 @@
 {
     "app-id" : "org.gnome.Settings",
     "runtime" : "org.gnome.Platform",
-    "runtime-version" : "3.28",
+    "runtime-version" : "master",
     "sdk" : "org.gnome.Sdk",
     "command" : "gnome-control-center",
     "rename-desktop-file" : "gnome-control-center.desktop",