Deletion of an instance after disabling the hypervisor by a non-admin
user leaks the host fqdn in fault msg of instance.Removing the
'host' field from the error message of HypervisorUnavaiable
cause it's leaking host fqdn to non-admin users. The admin user will
see the Hypervisor unavailable exception msg but will be able to figure
on which compute host the guest is on and that the connection is broken.
Change-Id: I0eae19399670f59c17c9a1a24e1bfcbf1b514e7b
Closes-Bug: #1851587
(cherry picked from commit a89ffab832)
(cherry picked from commit ff82601204)
(cherry picked from commit c5abbd17b5)