notifications: Ignore error when dimissing an already dismissed notification

I just installed freedombox on a pioneer Lime 2 SBC. During the setup process at: https://freedombox.local/plinth/notification/upgrades-new-release/dismiss/?next=/plinth/sys/

I am getting the following error:

404
Requested page /plinth/notification/upgrades-new-release/dismiss/ was not found.
If you believe this missing page should exist, please file a bug at the FreedomBox Service (Plinth) project issue tracker.

I think freedombox is timing out or something.