title: Source filtering not working on kibana
body: <p>I am trying to exclude some field with <a href="https://www.elastic.co/guide/en/elasticsearch/reference/5.6/search-request-source-filtering.html" rel="nofollow noreferrer">source filtering.</a></p>
  <p>I create an index:</p>
  <pre><code>put testindex
  {
    &quot;mappings&quot;: {
      &quot;type1&quot;: {
        &quot;properties&quot;:{
          &quot;name&quot;: { &quot;type&quot;: &quot;text&quot;  },
          &quot;age&quot;: { &quot;type&quot;: &quot;integer&quot; }
        }
      }
    }
  }
  </code></pre>
  <p>insert a document:</p>
  <pre><code>put testindex/type1/a
  {
    &quot;name&quot;:&quot;toto&quot;,
    &quot;age&quot;:23
  }
  </code></pre>
  <p>and try a filtered query:</p>
  <pre><code>get testindex/_search
  {
    &quot;_source&quot;: {
          &quot;excludes&quot;: [ &quot;age&quot; ]
      },
    &quot;query&quot;: {
      &quot;bool&quot;: {
        &quot;should&quot;: []
      }
    }
  } 
  </code></pre>
  <p>the result is:</p>
  <pre><code>&quot;hits&quot;: [
    {
      &quot;_index&quot;: &quot;testindex&quot;,
      &quot;_type&quot;: &quot;type1&quot;,
      &quot;_id&quot;: &quot;a&quot;,
      &quot;_score&quot;: 1,
      &quot;_source&quot;: {
        &quot;name&quot;: &quot;toto&quot;,
        &quot;age&quot;: 23
      }
    }
  ]
  </code></pre>
  <p>I don't understand why it does not hide the &quot;age&quot; field in _source.
  _source: false give the same result.<br />
  I used elasticsearch &amp; kibana 5.6</p>