Upgrading to 11.0.0 breaks existing JIRA configurations

Steps to reproduce :

• Using a previous version of the JIRA integration, set-up a remote JIRA server in the wiki administration using the JIRA Administration app (https://extensions.xwiki.org/xwiki/bin/view/Extension/JIRA/JIRA%20Administration/)
• Note that before 11.0.0, the option "Authentication type" is not proposed when configuring basic authentication ; as only basic authentication is supported.
• Verify that the extension works well by setting-up a simple JIRA macro with the configured server, showing the status of one ticket.
• Upgrade to 11.0.0 and restart XWiki
• Navigating to the jira macro, observe that the status of the ticket is not displayed anymore. Observe that nothing is being displayed (no error message).
• In the wiki administration, update the property "Authentication type" of the configured server and set it to "Basic auth", observe that this solves the problem

Marking as blocker as there is no fallback on basic auth for configuration created before 11.0.0, and as no error message or documentation is provided for administrators to understand the issue.