The behaviour of the `include` module is badly defined (it try to choose
between statically importing the tasks and dynamically including them)
and can cause problems depending on any number of constraints (mostly if
it choose the wrong behaviour).
Replace it with the `import_tasks` (always statically import tasks) unless
the `include` is in a loop in which case we replace it with
`include_tasks` (always dynamically include tasks).
Now the list of whitelisted ip addresses can be updated simply by
including the specific tasks in an external playbook without polluting
our role list.
This change takes effect for nginx, apache and fail2ban.