title: Django admin inline instances only if they exist
body: <p>After the "Area Tecnici" formset, there are only inline instances, but some of them are empty. How can I avoid displaying empty heads? I just want to inline a modelAdmin inline instance if it has some instances </p>
  
  <p>(e.g. "S.L. Formazioni" and "HACCP" have some instances, but "S.L. Valutazioni" and "Prestazioni &amp; Servizi" don't, so I don't want to inline "S.L. Valutazioni" and "Prestazioni &amp; Servizi")</p>
  
  <p><a href="https://imageshack.com/i/kmHTELYPp" rel="nofollow">Click here to see the screenshot</a></p>