[CentOS] Stop the FUD Xen is not deprecated

> It makes a difference. All of what I hear about KVM clearly states that 
> its performance is much worse than a paravirtualized RHEL/CentOS.
>
>   

i never mentioned anything about performance - pvirt works very well for 
me right now on a large scale so with 'support' being around for over 6 
years i see no reason to try anything else at the moment.