requirePrivilegeForUploadURL returned early on an empty URL, which was correct
while an empty URL meant "do not upload": there was no destination for
--upload-bundle-insecure to weaken. Now an empty URL means "use the destination
the management server published", so an unprivileged local caller could send
upload=true with an empty URL and uploadInsecure=true and have the root daemon
PUT the bundle to that destination with TLS verification disabled.
Gate the insecure flag on the empty-URL path too. A named URL keeps its existing
order, so a malformed one still reports InvalidArgument rather than a privilege
error.
riccardom