title: Elasticsearch: Disable indexing but apply copy_to for a field
body: <p>I am trying to use a field for only copying purpose and not to index itself with below mapping  </p>
  
  <pre><code>        "Line2": {
              "type":     "text",
              "copy_to": "AllFields" ,
              "enabled": false
          }
  </code></pre>
  
  <p>But getting exception</p>
  
  <blockquote>
    <p>{"error":{"root_cause":[{"type":"mapper_parsing_exception","reason":"Mapping
    definition for [Line2] has unsupported parameters:  [enabled :
    false]"}],"type":"mapper_parsing_exception","reason":"Failed to parse
    mapping [_doc]: Mapping definition for [Line2] has unsupported
    parameters:  [enabled :
    false]","caused_by":{"type":"mapper_parsing_exception","reason":"Mapping
    definition for [Line2] has unsupported parameters:  [enabled :
    false]"}},"status":400}</p>
  </blockquote>
  
  <p>Can this be done ?</p>
  
  <p><strong>ES version : 6.7</strong></p>