Variable expansion breaks when calling vars['key']

[Donien]

Like described in #266 variable expansion can break when referring a variable via vars['key'] instead of using key directly.

This can be a problem if, e.g., you want to define some components of say icingaweb2 within your hostvars and want to refer to them in your playbook's vars key.

Example:

test.yml

---
- name: Test
  hosts: localhost

  vars:
    foo: "{{ bar }}"

  tasks:
    - name: Directly
      debug:
        msg: "{{ foo }}"

    - name: Via vars
      debug:
        msg: "{{ vars['foo'] }}"   

ansible-playbook --connection local -i localhost, test.yml -e bar=value

Output:

PLAY [Test] ******************************************************************************************************

TASK [Gathering Facts] *******************************************************************************************
ok: [localhost]

TASK [Directly] **************************************************************************************************
ok: [localhost] => {
    "msg": "value"
}

TASK [Via vars] **************************************************************************************************
ok: [localhost] => {
    "msg": "{{ bar }}"
}

PLAY RECAP *******************************************************************************************************
localhost                  : ok=3    changed=0    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0

---

Proposed solution

Like it was previously fixed for icinga2 in #266 we could change all occurrences of vars[key].sub.key... to just key.sub.key... within all roles.