Update modals.js

make sure that were actually handling a `.modal` element.

lib/js/modals.js

@@ -20,6 +20,6 @@
 
   window.addEventListener('touchend', function (event) {
     var modal = getModal(event);
-    if (modal) modal.classList.toggle('active');
+    if (modal && modal.classList.contains('modal')) modal.classList.toggle('active');
   });
-}();
+}();