API: Removing value (link to an external resource) not possible

[s3flsago]

DELETE /api/entities/{id}/values/{prefixedKey}

Removing the link to https://serlo.org/1535 is not possible:
<Test_Entity> sdo:isPartOf <https://serlo.org/1535> .

[pajoma]

Fixed, please test again

[s3flsago]

For the prefixedKeys "sdo.isPartOf" and "skos:prefLabel" I receive:

"status": 400,
"error": "Bad Request",
"message": "value parameter should be a URI, BNode or Literal",

[pajoma]

Please test again

[s3flsago]

Tested removing values with the entitygraph python client for sdo.isPartOf, schema.isPartOf and skos.prefLabel.
Everything worked fine. Thanks!