Fix COF membership unittest

We did not reload the right user from the database

cof/tests.py

@@ -1,8 +1,6 @@
-from django.contrib.auth.models import Group, Permission, User
-from django.contrib.contenttypes.models import ContentType
 from django.test import TestCase
 
-from cof.models import CofProfile
+from cof.models import CofProfile, get_cof_assoc
 
 from gestion.tests import create_profile
 
@@ -15,13 +13,13 @@ def create_cofprofile(username):
 class TestCofProfile(TestCase):
     def test_str(self):
         cofp = create_cofprofile('foo')
-        # XXX. should by default new CofProfiles be COF members?
+
+        # CofProfiles are not cof members by default
         self.assertFalse(cofp.profile.user.has_perm('cof.member'))
+
         # adding/removing a user from the group should impact the
         # permission
-        group = Group.objects.get(name='cof_members')
+        group = get_cof_assoc().members_group
         cofp.profile.user.groups.add(group)
-        cofp.save()
-
-        cofp = CofProfile.objects.first()
+        cofp = CofProfile.objects.get(pk=cofp.pk)
         self.assertTrue(cofp.profile.user.has_perm('cof.member'))