Fix installing custom JDBC driver

[morgan-patou]

When not using the internal DB but instead using the external one, the JDBC driver is supposed to be provided inside the configuration_files/db_connector_repo and/or configuration_files/db_connector_sync. However, the roles for the repository and sync are currently using a source value using inventory_dir, which doesn't exist apparently. It's the only 2 path using that:

$ grep -ri '/configuration_files/' playbooks roles | grep -v molecule
playbooks/pki.yml:    actual_pki_dir: "{{ pki_dir | default('../configuration_files/pki') }}"
roles/repository/tasks/main.yml:        src: "{{ inventory_dir }}/configuration_files/db_connector_repo/"
roles/repository/tasks/main.yml:        src: "{{ role_path }}/../../configuration_files/licenses/"
roles/repository/tasks/main.yml:        src: "{{ role_path }}/../../configuration_files/keystores/"
roles/nginx/tasks/vhosts.yml:        src: "{{ role_path }}/../../configuration_files/ssl_certificates/{{ item.cert_key }}"
roles/nginx/tasks/vhosts.yml:        src: "{{ role_path }}/../../configuration_files/ssl_certificates/{{ item.cert_crt }}"
roles/sync/tasks/main.yml:        src: "{{ inventory_dir }}/configuration_files/db_connector_sync/"
$
$ grep -ri inventory_dir *
roles/repository/tasks/main.yml:        src: "{{ inventory_dir }}/configuration_files/db_connector_repo/"
roles/sync/tasks/main.yml:        src: "{{ inventory_dir }}/configuration_files/db_connector_sync/"
$

As mentioned in #716, I aligned the path in this PR with the other places that used the configuration_files folder. Tested successfully, the deployment is successful and Alfresco is working properly as well.

[gionn]

we probably need to refactor all of these to be role arguments which just provide a path, but at least now is working and consistent with similar tasks.

Thanks!