chore: apply F811 linter rule to eliminate redefined imports and methods (#2412)

api/controllers/service_api/dataset/document.py

@@ -1,7 +1,6 @@
 import json
 
 from flask import request
-from flask_login import current_user
 from flask_restful import marshal, reqparse
 from sqlalchemy import desc
 from werkzeug.exceptions import NotFound