title: Elasticsearch exclude bool "term" from getting highlighted
body: <p>I have the following elastic search query with query string that should match all the fields and term query should match the respective fields given below. I want only the query_string to be part of the highlight.  When i use required_field_match it highlights only the term "email" on the channel field. without required_field_match it matches "email" and query_string on all the fields which i dont want. Can you let me know how to exclude "channel" field from highlight ?</p>
  
  <pre><code> {
     "query":{
        "bool":{
           "must":[
              {
                 "term":{
                    "channel":"email"
                 }
              },
              {
                 "query_string":{
                    "query":"\"payment type\"",
                    "default_operator":"AND"
                 }
              }
           ]
        }
     },
     "highlight":{
        "pre_tags":[
           "&lt;span class='highlight'&gt;"
        ],
        "post_tags":[
           "&lt;/span&gt;"
        ],
        "require_field_match":false,
        "fields":{
           "requestSummary":{
              "number_of_fragments":0
           },
           "emails.emailBody":{
              "number_of_fragments":0
           },
           "chatTextArray.text":{
              "number_of_fragments":0
           },
           "chatTextArray.name":{
              "number_of_fragments":0
           }
        }
     },
     "facets":{
        "channel":{
           "terms":{
              "field":"channel"
           }
        },
        "siteId":{
           "terms":{
              "field":"siteId"
           }
        },
        "closeDt":{
           "terms":{
              "field":"closeDt"
           }
        },
        "srId":{
           "terms":{
              "field":"srId"
           }
        }
     }
  }
  </code></pre>
  
  <p><strong>Search results:</strong></p>
  
  <pre><code>    {
         "highlight":{
            "emails.emailBody":[
               "helps keep your information safe, visit:  http://pages.half.ebay.com/help/policy/privacy.html#toc-02 
  In this &lt;span class='highlight'&gt;email&lt;/span&gt;"
            ],
            "requestSummary":[
               "Change &lt;span class='highlight'&gt;payment&lt;/span&gt; &lt;span class='highlight'&gt;type&lt;/span&gt;"
            ]
         }
      }
  </code></pre>