Remove ovs_use_veth from cloud-admin-guide

Remove direction to set ovs_use_veth to true from cloud-admin-guide.
It's not required for recent kernels, and for those who aren't using
recent kernels we catch it in the install guide.

As this guide came into being after all supporting distributions had
moved to provide namespaces support I do not think we need to cater to
that situation here.

Change-Id: Ie0fa23bfdfcc3454988ead175ef0388f6a0602ba
Updated from global requirements

Change-Id: I5b35d45a6237e8cc532cff5472251e689516324f
Merge "Updated from global requirements"
Merge "Remove ovs_use_veth from cloud-admin-guide"