[gnome-photos] CI: Fix the caching

[Debarshi Ray <debarshir src gnome org>]

commit 81693cd0525b801df1ef0103e8eaebc4fd23f591
Author: Jordan Petridis <jpetridis gnome org>
Date:   Wed Sep 26 18:08:13 2018 +0300

    CI: Fix the caching
    
    Do not try to cache .flatpak-builder/cache. It does not work because
    Gitlab zips it which causes OSTree to break. Instead we can try to
    cache the git and download sources.
    
    https://gitlab.gnome.org/GNOME/gnome-photos/merge_requests/46
    https://gitlab.gnome.org/GNOME/gnome-photos/merge_requests/60

 .gitlab-ci.yml | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 46151db4..58583cd5 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -44,7 +44,8 @@ flatpak:
         expire_in: 2 days
     cache:
         paths:
-            - .flatpak-builder/cache
+            - .flatpak-builder/downloads
+            - .flatpak-builder/git
 
 review:
     stage: review