Fix cgi DeprecationWarning

Author: adamchainz

google/cloud/storage/blob.py

@@ -18,7 +18,6 @@
 """
 
 import base64
-import cgi
 import copy
 import hashlib
 from io import BytesIO
@@ -27,6 +26,7 @@
 import mimetypes
 import os
 import re
+from email.message import Message
 from urllib.parse import parse_qsl
 from urllib.parse import quote
 from urllib.parse import urlencode
@@ -1628,7 +1628,9 @@ def download_as_text(
  return data.decode(encoding)
 
  if self.content_type is not None:
- _, params = cgi.parse_header(self.content_type)
+ message = Message()
+ message["content-type"] = self.content_type
+ params = dict(message.get_params()[1:])
  if "charset" in params:
  return data.decode(params["charset"])