fix bug 1076874 and bug 1045187 (translated emails)

it won't show up in prod since the log level isn't set to debug there, this basically the better `print`


> Am 02.10.2014 um 21:31 schrieb luke crouch <notifications@github.com>:
> 
> In kuma/users/tasks.py:
> 
> >          context = {'username': user.username}
> > -        content_plain = render_to_string('users/email/welcome/plain.ltxt',
> > -                                         context)
> > -        content_html = render_to_string('users/email/welcome/html.ltxt',
> > -                                        context)
> > -
> > -        email = EmailMultiAlternatives(
> > -            _('Take the next step to get involved on MDN!'),
> > -            content_plain,
> > -            constance.config.WELCOME_EMAIL_FROM,
> > -            [user.email],
> > -        )
> > -        email.attach_alternative(content_html, 'text/html')
> > -        email.send()
> > +        log.debug('Using the locale %s to send the welcome email', locale)
> Remove this debug message?
> 
> —
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