fix misprint

app/core/background/ton_service.py

@@ -264,7 +264,7 @@ async def main_fn(memory):
                         blockchain_task.meta = {
                             **blockchain_task.meta,
                             'sign_created': sign_created,
-                            'signed_message': query_boc,
+                            'signed_message': query_boc.hex(),
                         }
                         await session.commit()
                         make_log("TON", f"Created signed message for task {blockchain_task.id}" + '\n' + traceback.format_exc(), level="info")