[Docs] Make the security note readable.
[Docs] Make the security note readable.

This was really unreadable for me. I hope it's clearer now.

Change-Id: I45d86673ba32dc97dba4b5c5e3c2c576ef1d04ad

openstack/openstack-ansible,cloudnull/os-ansible-deployment,stackforge/os-ansible-deployment,yanyao/openstack-ansible,weezer/openstack-ansible,weezer/openstack-ansible,BjoernT/os-ansible-deployment,bunchc/openstack-ansible,cloudnull/os-ansible-deployment,BjoernT/os-ansible-deployment,BjoernT/openstack-ansible,robb-romans/openstack-ansible,bunchc/openstack-ansible,cfarquhar/openstack-ansible,os-cloud/os-ansible-deployment,openstack/openstack-ansible,os-cloud/os-ansible-deployment,Logan2211/openstack-ansible,yanyao/openstack-ansible,stackforge/os-ansible-deployment,Logan2211/openstack-ansible,BjoernT/os-ansible-deployment,cfarquhar/openstack-ansible,BjoernT/openstack-ansible,robb-romans/openstack-ansible