tripleo container image delete has a misleading error when image doesn't exist

[Alex Schultz]

[centos@undercloud foo]$ sudo openstack tripleo container image delete --yes docker://undercloud.ctlplane.localdomain:8787/library/centos:7
[centos@undercloud foo]$ sudo openstack tripleo container image delete --yes docker://undercloud.ctlplane.localdomain:8787/library/centos:7
Unable to remove due to permissions. Please prefix command with sudo.
[Errno 2] No such file or directory: '/var/lib/image-serve/v2/library/centos/manifests'
[centos@undercloud foo]$

The 2nd delete probably shouldn't reference running with sudo since it's Errno 2 (no such file) instead of Errno 13 (permission denied)

[centos@undercloud foo]$ openstack tripleo container image delete --yes docker://undercloud.ctlplane.localdomain:8787/tripleomaster/centos-binary-mistral-executor:current-tripleo
Unable to remove due to permissions. Please prefix command with sudo.
[Errno 13] Permission denied: '/var/lib/image-serve/v2/tripleomaster/centos-binary-mistral-executor/manifests/current-tripleo.type-map'

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/709087

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/709087
Committed: https://git.openstack.org/cgit/openstack/python-tripleoclient/commit/?id=54494d2311892cf0b7f3e13705faa3922fb11517
Submitter: Zuul
Branch: master

commit 54494d2311892cf0b7f3e13705faa3922fb11517
Author: Russell Tweed <email address hidden>
Date: Fri Feb 21 10:07:51 2020 +0000

    Only show sudo hints when relevant

    Error message suggesting use of sudo was showing for all exceptions when deleting an image. This change restricts this to only show the 'use sudo' hint when a permissions problem has actually occurred.

    Change-Id: Id976f04e24ce12be0f7b7b3cc9e00487b31efe30
    Closes-Bug: 1859729