//Put in the header
<?php
    if ($this->countModules('sidebar-right') )
  {
    $counter = "col-sm-9";
  }
    else
  {
    $counter = "col-sm-12";
  }
?>

//Markup
    <div class="content-wrapper">
      <section class="content">
        <div class="row">
          <div class="<?php echo $counter; ?>">
            <jdoc:include type="message" />
            <jdoc:include type="component" />
         </div>

          <?php if ($this->countModules('sidebar-right')) : ?>
            <div class="col-sm-3">
              <jdoc:include type="modules" name="sidebar-right" style="xhtml" />
            </div>
          <?php endif; ?>

        </div>
      </section>
    </div>