Calling loadSpec() doesn't update the Download or View links

[ianjevans]

If you load a different spec programmatically using loadSpec() the Download OpenAPI Spec and View OpenAPI Spec (New Tab) buttons don't update the spec target.

So if you initially load A.json, then call loadSpec() to call B.json, the download/view buttons will download/view A.json.

Calling setAttribute('spec-url', url) works correctly.