python3: encoding variations in csv importer

src/authentic2/csv_import.py

@@ -28,6 +28,7 @@ from django.core.validators import RegexValidator
 from django.db import IntegrityError
 from django.db.transaction import atomic
 from django.utils import six
+from django.utils.encoding import force_text
 from django.utils.translation import ugettext as _
 
 from django_rbac.utils import get_role_model
@@ -120,7 +121,7 @@ class CsvImporter(object):
 
         def parse_csv():
             try:
-                content = input_fd.read().encode('utf-8')
+                content = force_text(input_fd.read().encode('utf-8'))
             except UnicodeDecodeError:
                 self.error = Error('bad-encoding', _('Bad encoding'))
                 return False