Fixed #2898 -- Added missing ngettext import to django.db.models.fields.related

git-svn-id: http://code.djangoproject.com/svn/django/trunk@3926 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/db/models/fields/related.py

@@ -2,7 +2,7 @@ from django.db import backend, transaction
 from django.db.models import signals, get_model
 from django.db.models.fields import AutoField, Field, IntegerField, get_ul_class
 from django.db.models.related import RelatedObject
-from django.utils.translation import gettext_lazy, string_concat
+from django.utils.translation import gettext_lazy, string_concat, ngettext
 from django.utils.functional import curry
 from django.core import validators
 from django import forms