refactor code (#583)

### What problem does this PR solve?

### Type of change

- [x] Refactoring

rag/svr/task_executor.py

@@ -26,7 +26,7 @@ import traceback
 from functools import partial
 
 from api.db.services.file2document_service import File2DocumentService
-from rag.utils import MINIO
+from rag.utils.minio_conn import MINIO
 from api.db.db_models import close_connection
 from rag.settings import database_logger
 from rag.settings import cron_logger, DOC_MAXIMUM_SIZE
@@ -35,7 +35,7 @@ import numpy as np
 from elasticsearch_dsl import Q
 from multiprocessing.context import TimeoutError
 from api.db.services.task_service import TaskService
-from rag.utils import ELASTICSEARCH
+from rag.utils.es_conn import ELASTICSEARCH
 from timeit import default_timer as timer
 from rag.utils import rmSpace, findMaxTm