erm.. use proper id

doc/eigendoxy_footer.html.in

@@ -26,12 +26,12 @@ $generatedby &#160;<a href="http://www.doxygen.org/index.html">
   (function() {
     var u="//stats.sylphide-consulting.com/matomo/";
     _paq.push(['setTrackerUrl', u+'piwik.php']);
-    _paq.push(['setSiteId', '1']);
+    _paq.push(['setSiteId', '20']);
     var d=document, g=d.createElement('script'), s=d.getElementsByTagName('script')[0];
     g.type='text/javascript'; g.async=true; g.defer=true; g.src=u+'piwik.js'; s.parentNode.insertBefore(g,s);
   })();
 </script>
-<noscript><p><img src="//stats.sylphide-consulting.com/matomo/piwik.php?idsite=1&rec=1" style="border:0;" alt="" /></p></noscript>
+<noscript><p><img src="//stats.sylphide-consulting.com/matomo/piwik.php?idsite=20&rec=1" style="border:0;" alt="" /></p></noscript>
 <!-- End Matomo Code -->
 
 </body>