Where did the “Import boot images” button go?

We no longer seem to have the “Import boot images” button on the clusters listing page. In fact I am no longer seeing any indication at all anywhere of my boot images, except this notice on my cluster's page:

«
Warning: this cluster has no boot images!

This cluster needs boot images in order to boot the nodes it controls. Make sure that the cluster controller has access to the Ubuntu archive, and start the import by clicking the "Import boot images" button on the cluster listing page.
»

Following the link to the cluster listing page doesn't get me to an import button. I'm guessing that the import now goes through more frequent automatic runs, and is also global rather than specific to a cluster, but then that message I quoted needs updating. Probably others as well, and the UI shown in docs/media/import-images.png.