Adding option to force refresh of getent_passwd

[Julien5858]

Hello,

This little addition can be usefull if like me you are using this role as a part of a workflow.

This workflow gets the getent facts at the beginning of his run but the users can be modified during it. So I had this case where the os_hardening role was trying to run stuff on users which do not exist anymore.

Setting this fact could be an easy way to handle this behavior.

Thanks, Julien.