fixes modal window closing bug

Closes #239

Author: kennyadsl

source/javascripts/refills/coffeescript/modal.coffee

@@ -1,5 +1,5 @@
 $ ->
-  $("#modal-1").on "click", ->
+  $("#modal-1").on "change", ->
     if $(this).is(":checked")
       $("body").addClass "modal-open"
     else

source/javascripts/refills/modal.js

@@ -1,5 +1,5 @@
 $(function() {
-  $("#modal-1").on("click", function() {
+  $("#modal-1").on("change", function() {
     if ($(this).is(":checked")) {
       $("body").addClass("modal-open");
     } else {