Fix memcached docker image location

.gitlab-ci.yml

@@ -5,7 +5,7 @@ test:
   stage: container-test
   image: registry.git.autistici.org/pipelines/images/test/float-podman-runner:master
   services:
-    - name: docker.io/library/memcache:latest
+    - name: docker.io/library/memcached:alpine
       alias: memcache
     - name: docker.io/library/mysql:latest
       alias: mysql