Warning for boolean values sent to ES in numeric form

1. install nuxeo
2. start nuxeo
3. launch an NXQL query like:

   ecm:mixinType != 'HiddenInNavigation' AND ecm:isVersion = 0 AND ecm:currentLifeCycleState != 'deleted'
   

4. observe the behavior is normal
5. now install a standalone ES
6. configure Nuxeo to use the standalone version of ES and not the embedded version
7. retry the same query
8. observe the following in Nuxeo logs:

   2018-10-04 15:20:31,221 WARN  [I/O dispatcher 13] [org.elasticsearch.client.RestClient] request [GET http://localhost:9200/nuxeo/_search?typed_keys=true&ignore_unavailable=false&expand_wildcards=open&allow_no_indices=true&search_type=dfs_query_then_fetch&batched_reduce_size=512] returned 1 warnings: [299 Elasticsearch-5.6.12-cfe3d9f "searching using boolean value [0] is deprecated, please use [true] or [false]" "Thu, 04 Oct 2018 13:20:31 GMT"]
   

Expected behavior: there should be no warning when issuing a query containing a boolean.
Note: this is due to Elasticsearch deprecation of boolean numeric forms see the following link for further detail:
https://www.elastic.co/guide/en/elasticsearch/reference/5.6/boolean.html