adapt Container usage to new soko-web

src/Repository/CommunityRepository.php

@@ -1,19 +1,11 @@
 <?php namespace RVR\Repository;
 
 use RVR\PersistentData\Model\Community;
-use SokoWeb\PersistentData\PersistentDataManager;
 
 class CommunityRepository
 {
-    private PersistentDataManager $pdm;
-
-    public function __construct()
-    {
-        $this->pdm = new PersistentDataManager();
-    }
-
     public function getById(int $id): ?Community
     {
-        return $this->pdm->selectFromDbById($id, Community::class);
+        return \Container::$persistentDataManager->selectFromDbById($id, Community::class);
     }
 }