We can expect that occasionally a user clicks on a login link when
the token is expired. If the UserInfoTokenServices tries to
authenticate the user at that point, it can retain the option to
refresh the expired token if we preserve the state. Since the
state is in session scope all we need to do is to check that the
token that is being checked has the same value as the one in the
OAuth2ClientContext and re-use the context if it is.
Fixes gh-4251
96ba5ed32c