Fix serialization of ObjectClass

lib/mapObjects/CObjectClassesHandler.h

@@ -263,6 +263,7 @@ public:
 
 	template <typename Handler> void serialize(Handler &h, const int version)
 	{
+		h & id;
 		h & handlerName;
 		h & base;
 		h & objects;

lib/serializer/CSerializer.h

@@ -14,8 +14,8 @@
 
 VCMI_LIB_NAMESPACE_BEGIN
 
-const ui32 SERIALIZATION_VERSION = 817;
-const ui32 MINIMAL_SERIALIZATION_VERSION = 813;
+const ui32 SERIALIZATION_VERSION = 818;
+const ui32 MINIMAL_SERIALIZATION_VERSION = 818;
 const std::string SAVEGAME_MAGIC = "VCMISVG";
 
 class CHero;