title: Content-Type header [application/x-www-form-urlencoded] is not supported on Elasticsearch
body: <p>I used to have ElasticSearch 5.2, and just upgraded to 6.0. </p>
  
  <p>I am trying to create an index template following guide <a href="https://www.elastic.co/guide/en/elasticsearch/reference/current/indices-templates.html" rel="noreferrer">here</a>, but got error</p>
  
  <pre><code>Content-Type header [application/x-www-form-urlencoded] is not supported
  </code></pre>
  
  <p>My query is </p>
  
  <pre><code>curl -X PUT localhost:9200/_template/template_1 -d '
  {
    "index_patterns": ["te*", "bar*"],
    "mappings": {
      "type1": {
        "properties": {
          "host_name": {
            "type": "keyword"
          }
        }
      }
    }
  }'
  </code></pre>