[gobject-introspection/gnome-3-30] docker: add a separate docker image for the stable branch

[Christoph Reiter <creiter src gnome org>]

commit 3f9e2ec3c0e735c3e2f9de5abba46fe3a0f4509a
Author: Christoph Reiter <reiter christoph gmail com>
Date:   Mon Nov 5 21:18:40 2018 +0100

    docker: add a separate docker image for the stable branch

 .gitlab-ci.yml           | 2 +-
 .gitlab-ci/run-docker.sh | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 357e673f..fff5f6eb 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -1,7 +1,7 @@
 stages:
   - build
 
-image: registry.gitlab.gnome.org/gnome/gobject-introspection:v1
+image: registry.gitlab.gnome.org/gnome/gobject-introspection/3.30:v1
 
 cache:
   paths:
diff --git a/.gitlab-ci/run-docker.sh b/.gitlab-ci/run-docker.sh
index 77eff633..54855d30 100755
--- a/.gitlab-ci/run-docker.sh
+++ b/.gitlab-ci/run-docker.sh
@@ -2,7 +2,7 @@
 
 set -e
 
-TAG="registry.gitlab.gnome.org/gnome/gobject-introspection:v1"
+TAG="registry.gitlab.gnome.org/gnome/gobject-introspection/3.30:v1"
 
 sudo docker build --build-arg HOST_USER_ID="$UID" --tag "${TAG}" \
     --file "Dockerfile" .