[Checksums] If no configs exist prevent to run over empty list
{'login': 'patrickvonplaten', 'id': 23423619, 'node_id': 'MDQ6VXNlcjIzNDIzNjE5', 'avatar_url': 'https://avatars.githubusercontent.com/u/23423619?v=4', 'gravatar_id': '', 'url': 'https://api.github.com/users/patrickvonplaten', 'html_url': 'https://github.com/patrickvonplaten', 'followers_url': 'https://api.github.com/users/patrickvonplaten/followers', 'following_url': 'https://api.github.com/users/patrickvonplaten/following{/other_user}', 'gists_url': 'https://api.github.com/users/patrickvonplaten/gists{/gist_id}', 'starred_url': 'https://api.github.com/users/patrickvonplaten/starred{/owner}{/repo}', 'subscriptions_url': 'https://api.github.com/users/patrickvonplaten/subscriptions', 'organizations_url': 'https://api.github.com/users/patrickvonplaten/orgs', 'repos_url': 'https://api.github.com/users/patrickvonplaten/repos', 'events_url': 'https://api.github.com/users/patrickvonplaten/events{/privacy}', 'received_events_url': 'https://api.github.com/users/patrickvonplaten/received_events', 'type': 'User', 'site_admin': False}
[]
[]
Whoops I fixed it directly on master before checking that you have done it in this PR. We may close it Yeah, I saw :-) But I think we should add this as well since some datasets have an empty list of configs and then as the code is now it would fail. 

In this PR, I just make sure that the code jumps in the correct else if "there are no configs" as is the case for some datasets @mariamabarham  Sorry, I thought you meant a different commit . Just saw this one: https://github.com/huggingface/nlp/commit/7c644f284e2303b57612a6e7c904fe13906d893f
.

All good then :-) 
`movie_rationales` e.g. has no configs.
{'url': 'https://api.github.com/repos/huggingface/datasets/issues/43/reactions', 'total_count': 0, '+1': 0, '-1': 0, 'laugh': 0, 'hooray': 0, 'confused': 0, 'heart': 0, 'rocket': 0, 'eyes': 0}
{'url': 'https://api.github.com/repos/huggingface/datasets/pulls/43', 'html_url': 'https://github.com/huggingface/datasets/pull/43', 'diff_url': 'https://github.com/huggingface/datasets/pull/43.diff', 'patch_url': 'https://github.com/huggingface/datasets/pull/43.patch', 'merged_at': None}