Description of problem:

Misleading error message

401, message='Unauthorized', url=URL('https://registry.redhat.io/v2/aodh-api/tags/list')

is received, if repository is misconfigured and wrong non existing upstream repo from registry.redhat.io i filled in configuration

 Message is misleading and even diverts from troubleshooting repo configuration instead of login issues. 

How reproducible:

100%

Is this issue a regression from an earlier version:

no

Steps to Reproduce:

1. create new docker repository

2. registry url : https://registry.redhat.io

Upstream Repository Name: make one op, for example idontexist-api

3. sync repo

Actual behavior:

401, message='Unauthorized', url=URL('https://registry.redhat.io/v2/aodh-api/tags/list')

Expected behavior:

404 not found  Return error stating this repository with this name does not exists

Business Impact / Additional info: