[gnome-shell-extensions] ci: Set a default image

[Florian Müllner <fmuellner src gnome org>]

commit a317d790160045605dda898d0d97c60892252140
Author: Florian Müllner <fmuellner gnome org>
Date:   Sat Apr 11 00:13:13 2020 +0200

    ci: Set a default image
    
    All jobs but one use the same issue, so specify that globally instead
    of for each job.
    
    https://gitlab.gnome.org/GNOME/gnome-shell-extensions/-/merge_requests/116

 .gitlab-ci.yml | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 8e806e5..a168ea1 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -1,3 +1,5 @@
+image: registry.gitlab.gnome.org/gnome/gnome-shell/extension-ci:v1
+
 stages:
  - commit_check
  - source_check
@@ -21,7 +23,6 @@ check_commit_log:
         - merge_requests
 
 eslint:
-  image: registry.gitlab.gnome.org/gnome/gnome-shell/extension-ci:v1
   stage: source_check
   script:
     - eslint -o $LINT_LOG extensions --no-color || { cat $LINT_LOG; false; }
@@ -32,7 +33,6 @@ eslint:
     when: on_failure
 
 build-shell-extensions:
-  image: registry.gitlab.gnome.org/gnome/gnome-shell/extension-ci:v1
   stage: build
   script:
     - meson _build .
@@ -40,7 +40,6 @@ build-shell-extensions:
   <<: *only_default
 
 build-bundles:
-  image: registry.gitlab.gnome.org/gnome/gnome-shell/extension-ci:v1
   stage: build
   script:
     - ./export-zips.sh