The URL-destination check previously ran over request-body fields only. The
per-field logic moves into reject_url_valued_destination(field, value) so a
deployment name resolved from the request path runs the same check against the
same admin allowlist.
BREAKING CHANGE: a deployment name supplied in the request path that parses as
an http/https destination is now refused. Add the host to
`provider_url_destination_allowed_hosts` in litellm_settings to keep it working.
