Adding the ability of pass a list or list of lists in firewall_additional_rules and firewall_ip6_additional_rules

[gabops]

At the moment "firewall_additional_rules" and "firewall_ip6_additional_rules" only allow a single list. This does not allow to pass custom rules from several group vars the host can belong to. With this change we can do extracted from the README:

... For example in groups_vars/all.yml we can have:

    firewall_additional_rules_all:
      - iptables A INPUT -s 123.123.123.123/32 -j ACCEPT -m comment --comment 'Office'"

and then from the other group vars:

    firewall_additional_rules_databases:
      - iptables A INPUT -s 111.111.111.111/32 -j ACCEPT -m comment --comment 'Webservers' "

and finally from an hypothetical playbook for provisioning a database node we would have something like:

    firewall_additional_rules:
      - "{{ firewall_additional_rules_all }}"
      - "{{ firewall_additional_rules_databases }}"

As you can see, this gives the possiblity of set custom iptables rules from different levels.

...