🐛(redirect) fix routes base template path

[jmaupetit]

Purpose

The redirect application deployment fails with the following traceback:

The task includes an option with an undefined variable. The error was: No first item, sequence was empty.
         
The error appears to have been in '/app/tasks/deploy_get_stamp_from_route.yml': line 9, column 3, but may
be elsewhere in the file depending on the exact syntax problem.

The offending line appears to be:

# deploy_stamp we are looking for.
- name: Get route for application {{ app.name }} with prefix {{ prefix }}
  ^ here
We could be wrong, but this one looks like it might be an issue with
missing quotes.  Always quote template expression brackets when they
start a value. For instance:

    with_items:
      - {{ foo }}

Should be written as:

    with_items:
      - "{{ foo }}"

Proposal

Since we now declare explicitly routes for an application by creating one (or many) route*.yml.j2 template(s) for each application service, the redirect app base template was consider as a route and not a generic route template used for redirections. Now that this template is considered as private (prefixed with an underscore), it is ignored when trying to create or patch routes.