[Python-Dev] [Python-checkins] hooks: Fix checkbranch hook

[Éric Araujo]

> +        if branch in ('trunk', 'legacy-trunk',
> +                      '2.0', '2.1', '2.2', '2.3', '2.4', '3.0'):

Wouldn’t using a whitelist instead of a blacklist protect against new
named branches too?