Twitter link (lazily wrong icon, because not in Glyphicons...)

gui/index.html

@@ -438,6 +438,7 @@
         <li><a class="navbar-link" href="https://github.com/syncthing/syncthing/releases" target="_blank"><span class="glyphicon glyphicon-info-sign"></span>&ensp;<span translate>Changelog</span></a></li>
         <li><a class="navbar-link" href="https://github.com/syncthing/syncthing/issues" target="_blank"><span class="glyphicon glyphicon-warning-sign"></span>&ensp;<span translate>Bugs</span></a></li>
         <li><a class="navbar-link" href="https://github.com/syncthing/syncthing" target="_blank"><span class="glyphicon glyphicon-wrench"></span>&ensp;<span translate>Source Code</span></a></li>
+        <li><a class="navbar-link" href="https://twitter.com/syncthing" target="_blank"><span class="glyphicon glyphicon-send"></span>&ensp;Twitter</a></li>
       </ul>
     </div>
   </nav>