With baseurl=http://prerelease.keybase.io/rpm/x86_64/, media.1/media should 404?

I'm trying to add http://prerelease.keybase.io/rpm/x86_64 as a repo on openSUSE but it wants to try probing http://prerelease.keybase.io/rpm/x86_64/media.1/media as well. If I understand right, if the media.1/media doesn't exist, it ignores that and then uses the baseurl. But in this case, it's denying access, which causes zypper to error-out instead.

Related openSUSE bug report: https://bugzilla.opensuse.org/show_bug.cgi?id=1032348

This post here claims that having the media.1/media URL 404 instead of 403'ing works: https://forums.insynchq.com/t/repository-for-opensuse/954/60

Start with the repository URL and its media.1/media path, then review the linked openSUSE Bugzilla report and forum post for the expected repository-probing behavior. Confirm whether the path is controlled by the Keybase repository hosting or installer configuration; done means zypper can add the base URL without failing on the media.1/media response.

Written by the indexing model from the issue text.