Top level class numbers (skos:notation) not shown in hierarchy when switching to the hierarchy tab from the vocabulary info page

[danmichaelo]

Not sure if the title makes sense, but here's the case:

• If I go to the vocabulary info page https://data.ub.uio.no/skosmos/ddc/nb/ , then switch to hierarchy, class numbers for the top classes are not shown (and consequently the sorting is wrong).
• If I go directly to a concept, like https://data.ub.uio.no/skosmos/ddc/nb/page/1 , they are shown correctly.

The same behaviour is observed on http://dev.finto.fi/udcs/en/ , but is less prominent there because the top concepts have dummy class numbers ("----" and "-").

[osma]

Closing as duplicate of #483, entered just a few minutes ago :)
Nice animation!