Update client.asciidoc

as of https://github.com/elastic/elasticsearch/commit/42526ac28e07da0055faafca1de6f8c5ec96cd85
5.0.0 alpha2 have no settingsBuilder() method.

docs/java-api/client.asciidoc

@@ -51,7 +51,7 @@ Note that you have to set the cluster name if you use one different than
 
 [source,java]
 --------------------------------------------------
-Settings settings = Settings.settingsBuilder()
+Settings settings = Settings.builder()
         .put("cluster.name", "myClusterName").build();
 Client client = TransportClient.builder().settings(settings).build();
 //Add transport addresses and do something with the client...