Ignore index closed

Hi,

I have a problem when a index is closed in ElasticSearch.
The search give a 503 error.

In log :
```
error: "ClusterBlockException[blocked by: [FORBIDDEN/4/index closed];]"
...
```

We can get the index state in order to ignore the index closed. This state can be found with http://localhost:9200/_cluster/state :

```
metadata -> indices -> INDICE_NAME -> state
```