title: bootstrapTable header columns appearing twice
body: <p>Here is what is happening</p>
  
  <p><img src="https://i.stack.imgur.com/c51y2.png" alt="bootstrap header columns"></p>
  
  <p>I cant figure out why the titles in the columns are appearing twice like that. I have the same code on other pages and it does not do this.</p>
  
  <p><strong>JQUERY</strong></p>
  
  <pre><code>var $table = $('#table-javascript').bootstrapTable({
      method: 'get',
      url: 'bootstrap_database_email_history.php',
      height: 300,
      cache: false,
      striped: true,
      pagination: true,
      search: false,
      pageSize: 20,
      pageList: [20, 40, 60, 100, 200],
      minimumCountColumns: 2,
      clickToSelect: true,
      columns: [{
          field: 'date',
          title: 'Date',
          align: 'left',
          width: '100'
      },{
          field: 'email', 
          title: 'Email',
          align: 'left',
          width: '20'
      },{
          field: 'sent',
          title: 'Sent',
          align: 'center',
          width: '20'
      },{
          field: 'notsent',
          title: 'Not Sent',
          align: 'center',
          width: '20'
      }]
  });
  </code></pre>
  
  <p><strong>HTML</strong></p>
  
  <pre><code>&lt;table id="table-javascript"&gt;&lt;/table&gt;
  </code></pre>
  
  <p><strong>bootstrap_database_email_history.php</strong></p>
  
  <pre><code>&lt;?
  include('../includes/connect.php');
  $sql = "SELECT * FROM table WHERE this = '$this' ORDER BY ID DESC";
  $result = mysql_query($sql);
  $records = mysql_num_rows($result);
  if ($records == 0) {
      $data['posts'][$i] = $response[$i];
  }
  $i = 0;
  while ($row = mysql_fetch_array($result)) {
      $response[$i]['date'] = $row['date'];
      $response[$i]['email'] = $row['email'];
      $response[$i]['sent'] = $row['sent'];
      $response[$i]['notsent'] = $row['notsent'];
      $data['posts'][$i] = $response[$i];
      $i = $i+1;
      unset($slot);
  }
  echo json_encode($data['posts']);
  ?&gt;
  </code></pre>
  
  <p><strong>JSON RESPONSE</strong></p>
  
  <pre><code>[{
      "date":"04\/30\/15",
      "email":"user@user.com",
      "sent":"&lt;\/i&gt;",
      "notsent":""
  },{
      "date":"04\/30\/15",
      "email":"user@leader.com",
      "sent":"&lt;\/i&gt;",
      "notsent":""
  },{
      "date":"04\/30\/15",
      "email":"user@admin.com",
      "sent":"&lt;\/i&gt;",
      "notsent":""
  }]
  </code></pre>