Software enty (for external artifact) cannot be deleted

[easybe]

When trying to delete a software entry for an external URL I get the following error message:

Int the web browser's console I get:

util.js:102     DELETE https://goosebit.foo.net/api/v1/software 422
delete_request @ util.js:102
deleteSoftware @ software.js:269
action @ software.js:151
a @ datatables.min.js:30
r @ datatables.min.js:30
(anonymous) @ datatables.min.js:30
dispatch @ datatables.min.js:14
v.handle @ datatables.min.js:14
software.js:272 Deleting software list failed: Error: POST /api/v1/software failed for [1]
    at delete_request (util.js:119:15)
    at async deleteSoftware (software.js:269:9)
    at async U.action (software.js:151:17)

The associated rollout entry was deleted successfully.