Don't return html links in API responses

[lostdusty]

I was playing with the api while writing gobalt, and i saw that the api returns html code if the url provided is invalid, shown on the screenshot below:

I believe this shouldn't happen, and the api should return only regular text on the text response body.

[ethrythedev]

it seems as though that is what defines what the cobalt website returns, the api should ideally send an error code and the website shows whatever information should be shown