[algorithms] Cannot fork shared algorithm

This seems to work on publicly shared algorithms, but not team-shared ones.

For example: https://www.beat-eu.org/platform/algorithms/chichan/comp_histogram_similarity/8/

Is shared with system/administrators (which is all of us) and forking it hits a 404 on:

https://www.beat-eu.org/platform/api/v1/algorithms/chichan/comp_histogram_similarity/1/?fields=html_description,description,short_description

As you can see on the algorithm description at the Django admin interface, the algorithm is properly shared, so the forking should work:

https://www.beat-eu.org/platform/admin/algorithms/algorithm/665/?_changelist_filters=q%3Dchichan

My guess is that there is an issue somewhere in rest framework end point concerning team sharing.