[gnome-music/wip/mschraal/core] CI: Use stable runtime

[Marinus Schraal <mschraal src gnome org>]

commit 7297a18a8e5d8abe83cc8763cb8be7a2a3361646
Author: Marinus Schraal <mschraal gnome org>
Date:   Fri Jun 28 10:04:46 2019 +0200

    CI: Use stable runtime

 .gitlab-ci.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index c25e3c0b..e9d0efee 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -1,4 +1,4 @@
-image: registry.gitlab.gnome.org/gnome/gnome-runtime-images/gnome:master
+image: registry.gitlab.gnome.org/gnome/gnome-runtime-images/gnome:3.32
 stages:
   - check
   - build-flatpak