MultiServer: fix #4 for checksum

by Black Sliver

Author: Berserker66

WebHostLib/customserver.py

@@ -102,8 +102,9 @@ def load(self, room_id: int):
                     # games package could be dropped from static data once all rooms embed data package
                     del multidata["datapackage"][game]
                 else:
-                    data = Utils.restricted_loads(GameDataPackage.get(checksum=game_data["checksum"]).data)
-                    game_data_packages[game] = data
+                    row = GameDataPackage.get(checksum=game_data["checksum"])
+                    if row:  # None if rolled on >= 0.3.9 but uploaded to <= 0.3.8. multidata should be complete
+                        game_data_packages[game] = row.data
 
         return self._load(multidata, game_data_packages, True)