WebAuthn may cause a security exception if the provided APP_ID is not allowed for the
current origin. Therefore we should reattempt authentication without the appid
extension.
Also we should allow [u2f] as-well as [U2F] sections.
Signed-off-by: Andrew Thornton <art27@cantab.net>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>