Fix broken conditionals when using on ansible-core >= 2.19 because of some playbooks changes

[gianmarco-mameli]

Hello,
I’m using the collection on Ansible Core >= 2.19, and because of some changes on the playbook behavior handling the conditionals, some tasks fail with an error like:

TASK [netways.icinga.monitoring_plugins : Apt - install requested packages] ***************************************************************************************************************************************************************************************************************************************************
[ERROR]: Task failed: Conditional result (True) was derived from value of type 'list' at '/Users/user/.ansible/collections/ansible_collections/netways/icinga/roles/monitoring_plugins/tasks/main.yml:53:22'. Conditionals must have a boolean result.

Task failed.
Origin: /Users/user/.ansible/collections/ansible_collections/netways/icinga/roles/monitoring_plugins/tasks/install_on_Debian.yml:3:3

1 ---
2
3 - name: Apt - install requested packages
    ^ column 3

<<< caused by >>>

Conditional result (True) was derived from value of type 'list' at '/Users/user/.ansible/collections/ansible_collections/netways/icinga/roles/monitoring_plugins/tasks/main.yml:53:22'. Conditionals must have a boolean result.
Origin: /Users/user/.ansible/collections/ansible_collections/netways/icinga/roles/monitoring_plugins/tasks/install_on_Debian.yml:13:7

11   when:
12     - needed_packages is defined
13     - needed_packages
         ^ column 7

Broken conditionals can be temporarily allowed with the `ALLOW_BROKEN_CONDITIONALS` configuration option.

The doc reference Ansible Broken Conditionals
I’ve made some fixes, simply adding a length > 0 filter to the vars to be sure that on the when clause the result is a pure boolean
Let me know if that’s ok

Thanks