[ENH] update backup docker image

templates/backup.yaml.j2

 version: "2.1"
 services:
     backup_gitlab:
-        image: tecnativa/duplicity:postgres
+        image: remifilament/duplicity:postgres # Until https://github.com/Tecnativa/docker-duplicity/pull/324 is merged
+        # image: ghcr.io/tecnativa/docker-duplicity-postgres:master # Once https://github.com/Tecnativa/docker-duplicity/pull/324 is merged
         hostname: {{ inventory_hostname_short | lower | regex_replace('_','') }}-gitlab
         environment:
             DST: "swift://gitlab_{{ inventory_hostname|lower }}"

templates/backup2.yaml.j2

 version: "2.1"
 services:
     backup_gitlab:
-        image: tecnativa/duplicity:postgres
+        image: remifilament/duplicity:postgres # Until https://github.com/Tecnativa/docker-duplicity/pull/324 is merged
+        # image: ghcr.io/tecnativa/docker-duplicity-postgres:master # Once https://github.com/Tecnativa/docker-duplicity/pull/324 is merged
         hostname: {{ inventory_hostname_short | lower | regex_replace('_','') }}-gitlab
         environment:
             DST: "swift://gitlab_{{ inventory_hostname|lower }}"