[CentOS] RTL8111/8168B always 100mbps

From: Brian Mathis <brian.mathis+centos at betteradmin.com>

> If your first reaction is to disable auto-negotioation, please 
> update your ways.  We are a decade into the 21st century, after all.

Sure, I can update my ways.
I do want to live into the 21st century!  ^_^
But that does not solve this annoying auto-negotiation bug...

JD