[geary/mjog/ci-3-38] .gitlab-ci.yml: Fix stable Flatpak SDK not being found

[Michael Gratton <mjog src gnome org>]

commit 04a05bb4e4d35f9deff45a6d631120f820b232c5
Author: Michael Gratton <mike vee net>
Date:   Mon Oct 7 13:43:29 2019 +1100

    .gitlab-ci.yml: Fix stable Flatpak SDK not being found

 .gitlab-ci.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 82f6ab3bd..e2feb3b8f 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -81,7 +81,7 @@ ubuntu:
     expire_in: 2 days
 
 flatpak:
-  image: 'registry.gitlab.gnome.org/gnome/gnome-runtime-images/gnome:master'
+  image: 'registry.gitlab.gnome.org/gnome/gnome-runtime-images/gnome:3.38'
   variables:
     APP_ID: org.gnome.Geary.Devel
     FLATPAK_MODULE: geary