Misleading error message when authenticating REST API calls with API Key instead of API Token

Issue Summary

If you mistakenly use the API key (used to manage your organization via the Cloud Admin APIs) to authenticate calls against Jira Cloud REST API endpoints, you get below error message in return:

Basic authentication with passwords is deprecated. For more information, see: https://confluence.atlassian.com/cloud/deprecation-of-basic-authentication-with-passwords-for-jira-and-confluence-apis-972355348.html

Having a bit more generic/useful error message would be better.

Something like:

Authentication failed. Make sure you are using the email address and API Token (not API Key) to authenticate. For more details see: https://confluence.atlassian.com/cloud/deprecation-of-basic-authentication-with-passwords-for-jira-and-confluence-apis-972355348.html

Also, the link returned should explicitly mention the differences between API key and API Token.

Steps to Reproduce

1. Try to authenticate any Jira REST API call using an API key instead of an API Token 

Expected Results

A generic error message saying the authentication failed is returned 

Actual Results

A very specific error message about basic authentication with password being deprecated is returned:

Basic authentication with passwords is deprecated. For more information, see: https://confluence.atlassian.com/cloud/deprecation-of-basic-authentication-with-passwords-for-jira-and-confluence-apis-972355348.html

Workaround

No workaround.