fix #258 task_executor occupy cpu too much (#288)

### What problem does this PR solve?

Issue link:#285

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

rag/utils/minio_conn.py

@@ -58,7 +58,7 @@ class HuMinio(object):
 
 
     def get(self, bucket, fnm):
-        for _ in range(10):
+        for _ in range(1):
             try:
                 r = self.conn.get_object(bucket, fnm)
                 return r.read()