Website: move UBOSbox to discontinued section

Hi!

On Devices - Nextcloud the second device is actually discontinuned, see Indie Computing Corp. | Products :

We are currently not shipping new UBOSbox units. This is because as our supplier has discontinued the hardware we’ve been using.
We are investigating alternatives but have no timeline to announce at this time.

The device should be moved to the “Sold out/or not available any more” section at the bottom.

(I could not find a website feedback category here, so I posted it in “general”)

@Daphne @jospoortvliet Is there a new repo for the current web site to report these issues? The old repo does not reference anything GitHub - nextcloud/nextcloud.com: 🌏 Our website