Clarify what fail2ban_cidr_list variable for
The variable name fail2ban_cidr_list
doesn't express what we use it for in the ansible role. So change it to use a variable name that describes its purpose.
We use it to define the value for ips that can be whitelisted by fail2ban typically the internal ips. So change it to fail2ban_cidr_list
resolved in 0c0cadb4