Martijn van Groningen 15f30d689b
[CCR] Do not unnecessarily wrap fetch exception in a ElasticSearch exception and (#33777)
* [CCR] Do not unnecessarily wrap fetch exception in a ElasticSearch exception and
properly map fetch_exception.exception field as object.

The extra caused by level is not necessary here:

```
"fetch_exceptions": [
              {
                "from_seq_no": 1,
                "retries": 106,
                "exception": {
                  "type": "exception",
                  "reason": "[index1] IndexNotFoundException[no such index]",
                  "caused_by": {
                    "type": "index_not_found_exception",
                    "reason": "no such index",
                    "index_uuid": "_na_",
                    "index": "index1"
                  }
                }
              }
            ],
```
2018-09-17 22:33:37 +02:00
..