Invalid IDNA domains in email addresses passed to urlize raises exception

[Chris Lamb]

    >>> from django.utils.html import urlize
    >>> urlize('lol@dongs..com')
    [...]

    UnicodeError: label empty or too long

ie. Calls str.encode('idna') without a try-except block. Regression from https://code.djangoproject.com/changeset/17348 I think.

[Claude Paroz]

Thanks for the report, but this is known and a fix is ready for checkin in #17592.