Fix iwslt2017
_The documentation is not available anymore as the PR was closed or merged._ CI fails are just abut missing tags in the dataset card, merging ! FYI, 

The checksums have not been edited from the changes of .tgz to .zip files, and as a result a `ExpectedMoreDownloadedFiles` error occurs. Updating them in the `dataset_infos.json` should fix the error.  Thanks for reporting and sorry for the delay, I opened https://huggingface.co/datasets/iwslt2017/discussions/2 to fix this
The files were moved to google drive, I hosted them on the Hub instead (ok according to the license)

I also updated the `datasets_infos.json`