keystone_fernet cron jobs installed into wrong place in CentOS source build

User cron jobs are located under /var/spool/cron/$username in CentOS.

e.g.

Running crontab -e with user root will create a file /var/spool/cron/root <---- This is not a directory.

Should add if condition in keystone-fernet.json.j2

        {
            "source": "{{ container_config_directory }}/crontab",
{% if kolla_base_distro == 'centos' %}
            "dest": "/var/spool/cron/root",
{% else %}
            "dest": "/var/spool/cron/crontabs/root/fernet-cron",
{% endif %}
            "owner": "root",
            "perm": "0600"
        },