ulwgl_dl_util: be smarter about imports

ulwgl_dl_util.py

@@ -4,10 +4,7 @@
 from typing import Dict, List, Tuple, Any, Union
 from hashlib import sha512
 from shutil import rmtree
-from http.client import HTTPSConnection
-from http.client import HTTPConnection
-from http.client import HTTPResponse
-from http.client import HTTPException
+from http.client import HTTPSConnection, HTTPResponse, HTTPException, HTTPConnection
 from ssl import create_default_context
 from json import loads as loads_json
 from urllib.request import urlretrieve