title: Header HTML has 100% height with wkhtmltopdf 0.12
body: <p>I am using wkhtmltopdf 0.12 with wicked_pdf or pdfkit and the header takes almost 100% of the page height.</p>
  
  <p>It creates these problems :</p>
  
  <ul>
  <li>Pages are almost empty</li>
  <li>There are many more pages than it should</li>
  </ul>