was-thumbnail-service: deal with 404s from orig urls

[ndushay]

If looking up a memento url with id_ redirects to the original url, and the original url gives a 404 or similar un-thumbnailable response, what should happen?

options might include:

• fall back to wayback wrapped version of page when such an error encountered?
• never use id_ redirects and ALWAYS use wayback wrapped versions? <- yay! cheap and easy!
• fiddle with wayback wrap to remove it from the thumbnail generation?

@nullhandle this one's needs you ...

[ndushay]

example: https://swap.stanford.edu/20151012231536id_/https://ustr.gov/about-us/press-office/reports-and-publications/

[ndushay]

Are other institutions getting thumbs via openwayback that cope better with this redirection issue? E.g. British Library and Internet Archive.

[nullhandle]

I can't replicate behavior observed by @ndushay that visiting the example archived URL redirects to the live site. I don't believe this is a common case, but if other examples can be found, we should consult code and/or individuals from the aforementioned organizations.