clarify what we mean by "disable a failed host"
clarify what we mean by "disable a failed host"

Make this more obvious to those not familiar with nova service-disable.

Change-Id: I4de317619d41582cc4f104d1e5f2977d67a0c8e0
Signed-off-by: Adam Spiers <a3b1ac66d44425905084924ee6cef90b31d2e761@suse.com>

openstack/openstack-user-stories