add cause to elasticsearch exception message (#1213) (#1214)

Co-authored-by: Laura Trotta <153528055+l-trotta@users.noreply.github.com>

Author: github-actions[bot]

java-client/src/main/java/co/elastic/clients/elasticsearch/_types/ElasticsearchException.java

@@ -40,7 +40,7 @@ public class ElasticsearchException extends RuntimeException {
 
 	public ElasticsearchException(String endpointId, ErrorResponse response,
 			@Nullable TransportHttpClient.Response httpResponse) {
-		super("[" + endpointId + "] failed: [" + response.error().type() + "] " + response.error().reason());
+		super("[" + endpointId + "] failed: [" + response.error().type() + "] " + response.error().reason() + (response.error().causedBy() != null ? " - " + response.error().causedBy().reason() : null));
 		this.response = response;
 		this.endpointId = endpointId;
 		this.httpResponse = httpResponse;