delete_network.yml conditional always returns false

Issue description

The conditional in the delete_network task always evaluates to false causing the removal of docker networks to always be skipped.

Cause

The task for deleting docker networks (residing in src/molecule_docker/playbooks/tasks/delete_network.yml) executes based on a list of conditionals defined in the when option:

- name: Delete docker network(s)
  community.docker.docker_network:
    name: "{{ item.name }}"
    state: "absent"
  when:
    - docker_netname.exists
    - docker_netname.network.Labels.owner is not defined
    - docker_netname.network.Labels.owner == 'molecule'

Ansible uses an and operator between the list items to calculate the final conditional value. And because the label "owner" cannot be undefined and set to "molecule" at the same time. Currently this causes the when option to always evaluate to false. Depending on the desired behaviour this should be changed to either:

check if owner is not defined or set to molecule
check if owner is defined and set to molecule

Steps to reproduce the issue

create docker network under platforms in molecule.yml

platforms: 
- name: instance
image: {{ docker_image }}
networks:
  - name: test-net

create platform
```
molecule create
```

destroy platform

molecule destroy

Expected behaviour

Molecule should delete the network after destroying docker containers. stdout for molecule destroy in verbose mode:

TASK [Delete docker network(s)] ************************************************
changed: [localhost] => {"actions": ["Removed network test-net"], "changed": true}

Actual behaviour

Delete docker network(s) task is skipped. stdout for `molecule destroy' in verbose mode"

TASK [Delete docker network(s)] ************************************************
skipping: [localhost] => {"changed": false, "skip_reason": "Conditional result was False"}

ansible-community / molecule-docker