Prevent provisioned account updates that have no effect

[ChristophWurst]

Is your feature request related to a problem? Please describe.

It looks like we often update provisoined Mail accounts in the before controller middleware hook even if there are no changes. This slows down every Mail request a tiny bit.

SQL: update oc_mail_accounts set provisioning_id = ? where id = ?

Describe the solution you'd like

Only update the account if necessary.

Describe alternatives you've considered

No response

Additional context

No response