fix flows cache

Author: avdosev

lib/pages/article/article.dart

@@ -170,7 +170,7 @@ class _ArticlePageState extends State<ArticlePage> {
       final preview = PostPreview(
         id: articleId,
         title: post.title,
-        hubs: [],
+        flows: [],
         publishDate: post.publishDate,
         statistics: Models.Statistics.zero(),
         author: post.author,

lib/stores/habr_storage.dart

@@ -114,7 +114,7 @@ class HabrStorage {
 
         return PostPreview(
           id: post.id,
-          hubs: [],
+          flows: [],
           title: post.title,
           publishDate: post.publishDate,
           statistics: Statistics.zero(),