Bug
===
When we copy a GMail outgoing / incoming mail server, an error
occurs because we try to refetch the access token, based on the same
authorization code (which can be used only once).

To fix this issue, we do not copy the authorization code (and other
related fields).

Task-2751996

X-original-commit: 2879976160bc0777cde1368ed2b69ce821c85ff1
Part-of: odoo/odoo#87498