Fix URI of schema.org
Either is valid according to https://schema.org/docs/gs.html ; but we need to pick one, as they are opaque identifiers. And codemeta chose http:// (because it was the only one to be valid back then), so we should stick to this one.
Sorry @ardumont, I made the mistake in !277 (closed)
Migrated from D7212 (view on Phabricator)