[1.5.x] Typo in i18n docs.

:attr:`~django.db.models.Options.verbose_name` and

:attr:`~django.db.models.Options.verbose_name_plural` options rather than

relying on the fallback English-centric and somewhat naïve determination of

verbose names Django performs bu looking at the model's class name::

verbose names Django performs by looking at the model's class name::

    from django.utils.translation import ugettext_lazy as _