Update header.html

_includes/header.html

@@ -19,11 +19,11 @@
                         Fahrplan
                     </a>
 		    </li> -->
-                <li>
+                <!-- <li>
                     <a href="https://tickets.hackimpott.de/c3e/hip/">
                         Tickets
                     </a>
-                </li>
+                </li> -->
                 <li>
                     <a href="https://wiki.hackimpott.de">
                         Wiki