title: Elasticsearch remove "one level" from the mapping
body: <p>I need to destructurate my index mapping.</p>
  
  <p>My index has the following mapping</p>
  
  <pre><code>  "A": {
      "properties": {
        "B": { 
          "properties": {
               -c
               -d
               -e
           }
        }
      }
    }
  </code></pre>
  
  <p>What I need is to delete "one level" in order to have a mapping like this:</p>
  
  <pre><code> "A": {
      "properties": {
              -c
              -d
              -e
        }
   }         
  </code></pre>
  
  <p>Is it possible to obtain this result without reindexing all my data?</p>