Resolve "Clicking on map with private comments might produce an error"

Closes #152 (closed)

frontend-js/src/main/js/gui/topMenu/TopMenu.js

@@ -171,7 +171,7 @@ TopMenu.prototype.init = function() {
     } else {
       refreshCommentButton.style.display = 'none';
     }
-    return self.getMap().refreshComments();
+    return self.getMap().refreshComments().then(null, GuiConnector.alert);
   };
   refreshCommentButton.onclick = (function() {
     return function() {