title: issue in setting cell value by row and column after merge in phpexcel
body: <p>I want to merge 1st <code>row A1 to H1</code> and input category 1 and <code>merge I1 to P1</code> and input category 2 as values. I am trying with this below code and it is merging columns which is fine but it is not inputting second category value. </p>
  
  <p>what is wrong here?</p>
  
  <pre><code>    $this-&gt;excel-&gt;getActiveSheet()-&gt;setCellValueByColumnAndRow(0, 1, "NetApp Nominator's Contact Information");        
      $this-&gt;excel-&gt;setActiveSheetIndex(0)-&gt;mergeCells('A1:H1');
  
      $this-&gt;excel-&gt;getActiveSheet()-&gt;setCellValueByColumnAndRow(1, 1, "NetApp manoj");        
      $this-&gt;excel-&gt;setActiveSheetIndex(0)-&gt;mergeCells('I1:P1');
  </code></pre>
  
  <p>Am using phpexcel.</p>