fix browser hang when listobjects is denied (#6385)

When Deny ListObjects policy is set on bucket, the browser
is hanging while trying to list the object. This is now
fixed by showing appropriate error message and an
empty object list.

Fixes #6371

browser/app/js/objects/reducer.js

@@ -50,6 +50,13 @@ export default (
         marker: action.marker,
         isTruncated: action.isTruncated
       }
+    case actionsObjects.RESET_LIST:
+      return {
+        ...state,
+        list: [],
+        marker: "",
+        isTruncated: false
+      }
     case actionsObjects.APPEND_LIST:
       return {
         ...state,