Fix state propragation of the backup codes provider

Starting with Nextcloud 14, the server knows the enabled/disabled
state of 2fa providers. While it will query that information if it's
unknown (on first use), it won't notice any changes. Thus, providers
have to propagate that information themselves.

Ref https://github.com/nextcloud/twofactor_totp/pull/263
Ref https://github.com/nextcloud/twofactor_u2f/pull/210



Signed-off-by: Christoph Wurst <christoph@winzerhof-wurst.at>