SBU download is failing

[pmeier]

This is happening since roughly a month (first detection in #6274), but was masked by #6268.

http://www.cs.virginia.edu/~vicente/sbucaptions/

The server is still up, but the path is no longer valid. I'll reach out to the author to see if this can be fixed. In the meantime we should probably disable the test.

cc @pmeier @YosuaMichael

[pmeier]

I've contacted the author of the paper and the new link is

https://www.cs.rice.edu/~vo9/sbucaptions/

Will send a PR to update our sources.

[pmeier]

The author provided me a link to the actual image archive rather than just an URL list. The website reads

Alternatively, if you're interested in the image collection for research purposes please email vicenteor@rice.edu

I'm checking back if it is ok for us to publish that link. That would simplify the download by quite a bit and would mean the discussion in #5706 is moot for now.