[libgda/LIBGDA_5.2] CI: switch to ubuntu latest to fix MySQL provider

[Daniel Espinosa Ortiz <despinosa src gnome org>]

commit 3bbd2632244a7304e3507434e599f0734c18667f
Author: Daniel Espinosa <esodan gmail com>
Date:   Fri Sep 17 11:16:23 2021 -0500

    CI: switch to ubuntu latest to fix MySQL provider

 .gitlab-ci.yml | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 87d56ccab..ebe063636 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -2,7 +2,7 @@
 # use the official gcc image, based on debian
 # can use verions as well, like gcc:5.2
 # see https://hub.docker.com/_/gcc/
-image: debian:stable
+image: ubuntu:latest
 
 services:
   - postgres:latest
@@ -18,7 +18,6 @@ variables:
   POSTGRES_HOST: postgres
   MYSQL_DATABASE: test
   MYSQL_ROOT_PASSWORD: test1
-  MYSQL_USER: root
   MYSQL_HOST: mysql
   G_MESSAGES_DEBUG: all
   DEPENDENCIES: gcc gettext gtk-doc-tools make autoconf