Flexget: BUG: Discover/Piratebay: "'NoneType' object has no attribute 'group'"

This has been happening to me on 2.3.3 - can’t see it mentioned, but sorry if it’s a dupe!

Traceback (most recent call last):
  File "/usr/local/lib/python2.7/dist-packages/flexget/task.py", line 472, in __run_plugin
    return method(*args, **kwargs)
  File "/usr/local/lib/python2.7/dist-packages/flexget/event.py", line 23, in __call__
    return self.func(*args, **kwargs)
  File "/usr/local/lib/python2.7/dist-packages/flexget/plugins/input/discover.py", line 290, in on_task_input
    return self.execute_searches(config, entries, task)
  File "/usr/local/lib/python2.7/dist-packages/flexget/plugins/input/discover.py", line 155, in execute_searches
    search_results = search.search(task=task, entry=entry, config=plugin_config)
  File "/usr/local/lib/python2.7/dist-packages/flexget/plugin.py", line 118, in wrapped_func
    return func(*args, **kwargs)
  File "/usr/local/lib/python2.7/dist-packages/flexget/plugins/sites/piratebay.py", line 151, in search
    entry['content_size'] = parse_filesize(size.group(1))
AttributeError: 'NoneType' object has no attribute 'group'

Config:

  moviesPBHQ:
    verify_ssl_certificates: no
    discover:
      what:
        - movie_list:
            list_name: allmyfilms
            strip_year: yes
      from:
        - piratebay:
            category: movies
    template: movietemplate
    priority: 80
    seen: local
    quality:
      - 720p+
      - webrip+