Backporting to Python 3.8. (Why did this ever work for younger versio…

…ns?)

nikola/utils.py

@@ -60,7 +60,7 @@
 from doit import tools
 from doit.cmdparse import CmdParse
 from nikola.packages.pygments_better_html import BetterHtmlFormatter
-from typing import Any, Dict, List, Mapping, Match, Optional, Tuple, Union
+from typing import Any, Dict, Iterable, List, Mapping, Match, Optional, Tuple, Union
 from unidecode import unidecode
 
 # Renames