Cannot delete Project Licenses if there is only one entry

[ashrafmr]

Nothing happens at all when clicking the 'Delete' button.
Tried action on Firefox and Edge browsers.

A POST request is sent, https://*****/api/settings/set
Body:
key=licensecheck.project-license-set

Response:
{"errors":[{"msg":"Either \u0027value\u0027, \u0027values\u0027 or \u0027fieldValues\u0027 must be provided"}]}

XHRPOSThttps://*****/api/settings/set
[HTTP/1.1 400 158ms]

Uncaught (in promise)
Response { type: "basic", url: "https://*****/api/settings/set", redirected: false, status: 400, ok: false, statusText: "", headers: Headers(7), body: ReadableStream, bodyUsed: false }

[derkoe]

I see this only happens if there is only one project license left - this last one cannot be deleted because SonarQube does not accept the empty value.