[glib/wip/ci-i686] CI: switch the debian stable image to i686

[Christoph Reiter <creiter src gnome org>]

commit 1a1bbf9bf48937be3a94ec3f13748af2c1cc45b1
Author: Christoph Reiter <creiter src gnome org>
Date:   Sat May 25 13:20:38 2019 +0200

    CI: switch the debian stable image to i686
    
    The debian image is used to test older dependencies and toolchains.
    This adds an older architecture to that list.

 .gitlab-ci.yml                      | 4 ++--
 .gitlab-ci/debian-stable.Dockerfile | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index d78f8cdb8..5af633836 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -53,8 +53,8 @@ fedora-x86_64:
       - "_build/${CI_JOB_NAME}-report.xml"
       - "_coverage"
 
-debian-stable-x86_64:
-  image: registry.gitlab.gnome.org/gnome/glib/debian-stable:v1
+debian-stable-i686:
+  image: registry.gitlab.gnome.org/gnome/glib/debian-stable:v2
   stage: build
   except:
     - tags
diff --git a/.gitlab-ci/debian-stable.Dockerfile b/.gitlab-ci/debian-stable.Dockerfile
index f10ebc071..899d8cc73 100644
--- a/.gitlab-ci/debian-stable.Dockerfile
+++ b/.gitlab-ci/debian-stable.Dockerfile
@@ -1,4 +1,4 @@
-FROM debian:stretch
+FROM i386/debian:stretch
 
 RUN apt-get update -qq && apt-get install --no-install-recommends -qq -y \
     bindfs \