fix #256: change error code from 403 to 401

[ngrigoriev]

Signed-off-by: Grigoriev, Nikolai [email protected]

#256

Proposed changes

• added new field to the tests to check the status code for the errors
• changed the status code to 401

Checklist

• [x ] I have read the contributing guidelines
• [x ] I have read the security policy
• [ x] I confirm that this pull request does not address a security
  vulnerability. If this pull request addresses a security vulnerability, I
  confirm that I got green light (please contact
  [email protected]) from the maintainers to push
  the changes.
• [x ] I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation within the code base (if appropriate)
• I have documented my changes in the
  developer guide (if appropriate)

Further comments

Documentation is already mentioning 401 so no updates are needed

[CLAassistant]

All committers have signed the CLA.

[ngrigoriev]

@aeneasr silly me, I have missed the e2e tests that need to be verified in addition to "go test ..."