Backport sleep for max_attempts

[hellysmile]

https://github.com/elastic/elasticsearch-py/pull/794/files

[hellysmile]

https://github.com/elastic/elasticsearch-py/blob/master/elasticsearch/transport.py#L310

[hellysmile]

https://github.com/aio-libs/aioelasticsearch/blob/master/aioelasticsearch/transport.py#L251