title: Elasticsearch rest client http over https issue
body: <p>I am trying the following API,</p>
  <pre><code>@Autowire private final RestHighLevelClient restHighLevelClient;
  var restClient = restHighLevelClient.getLowLevelClient();
      Response response = null;
      try {
        var request = new Request(&quot;GET&quot;, &quot;/_cat/indices?v&amp;format=json&quot;);
        response = restClient.performRequest(request);
      } catch (IOException e) {
        log.warn(e.toString(), e);
      }
  
      var entity = response.getEntity();
      if (entity != null) {
        log.info(&quot;content:&quot; + IOUtils.toString(entity.getContent(), StandardCharsets.UTF_8));
      }
  </code></pre>
  <p>The elasticsearch server is running on https, and this is bean to create the client</p>
  <pre><code>@Bean(destroyMethod = &quot;close&quot;)
    public RestHighLevelClient client() {
      var connUri = URI.create(esClusterUrl);
      String[] auth = connUri.getUserInfo().split(&quot;:&quot;);
  
      var credentialsProvider = new BasicCredentialsProvider();
      credentialsProvider.setCredentials(
          AuthScope.ANY, new UsernamePasswordCredentials(auth[0], auth[1]));
  
      var builder =
          RestClient.builder(new HttpHost(connUri.getHost(), connUri.getPort()))
              .setHttpClientConfigCallback(
                  httpClientBuilder -&gt;
                      httpClientBuilder.setDefaultCredentialsProvider(credentialsProvider));
      return new RestHighLevelClient(builder);
  </code></pre>
  <p>The error response, I am getting is</p>
  <pre><code>2021-04-11 21:13:07.822  WARN 40680 --- [           main] com.document.feed.util.ESMaintenance     : org.elasticsearch.client.ResponseException: method [GET], host [http://yew-739425389.eu-west-1.bonsaisearch.net:443], URI [/_cat/indices?v&amp;format=json], status line [HTTP/1.1 400 Bad Request]
  &lt;html&gt;
  &lt;head&gt;&lt;title&gt;400 The plain HTTP request was sent to HTTPS port&lt;/title&gt;&lt;/head&gt;
  &lt;body&gt;
  &lt;center&gt;&lt;h1&gt;400 Bad Request&lt;/h1&gt;&lt;/center&gt;
  &lt;center&gt;The plain HTTP request was sent to HTTPS port&lt;/center&gt;
  &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  <p>which is pretty much self explainatory, meaning I should be making https calls to the server, while I am doing http rest call. What can be the resolution?</p>