[gvfs] ci: Add possibility to specify default image

[Ondrej Holy <oholy src gnome org>]

commit 49170edbb1a8c7ad1f439c3ce7215b487bd39890
Author: Ondrej Holy <oholy redhat com>
Date:   Wed Jan 29 10:37:54 2020 +0100

    ci: Add possibility to specify default image
    
    Add easy way to specify default image for testing using TAG variable.
    The variable is now predefined to latest. But this allows to easy change
    the image if latest image is broken, or can be used for debugging.

 .gitlab-ci.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index c7edf813..f10de916 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -1,5 +1,5 @@
 fedora:
-    image: registry.gitlab.gnome.org/gnome/gvfs:latest
+    image: registry.gitlab.gnome.org/gnome/gvfs:$TAG
     script:
         - meson -Dinstalled_tests=true -Ddevel_utils=true -Dman=true --prefix /usr --werror build
         - ninja -C build install