Accept Terms value to be any iterable

[roxanebellot]

trafficstars

Fixes https://github.com/elastic/elasticsearch-dsl-py/issues/1641

[cla-checker-service[bot]]

❌ Author of the following commits did not sign a Contributor Agreement: 18f4f35076b28d39880ba621c710f29beee75228

Please, read and sign the above mentioned agreement if you want to contribute to this project

[roxanebellot]

I signed the CLA, please fix cla-checker-service.

[pquentin]

@roxanebellot Sorry for the delay getting back to you. You signed the CLA using your personal email, but the commit was made with your work email.

[miguelgrinberg]

Closing, since we cannot merge without a signed CLA.