adapt Container usage to new soko-web

src/PersistentData/Model/Place.php

@@ -4,7 +4,6 @@ use DateInterval;
 use DateTime;
 use SokoWeb\PersistentData\Model\Model;
 use SokoWeb\Http\Request;
-use SokoWeb\PersistentData\PersistentDataManager;
 use MapGuesser\Util\Geo\Position;
 use MapGuesser\Util\Panorama\Pov;
 
@@ -163,7 +162,7 @@ class Place extends Model
         $this->panoIdCached = $panoId;
         $this->panoIdCachedTimestamp = new DateTime();
 
-        (new PersistentDataManager())->saveToDb($this);
+        \Container::$persistentDataManager->saveToDb($this);
 
         return $panoId;
     }