Prevent conflicts in COF perm migration

There may be a conflict during the migration cof 0009 if the permissions
are referenced only by their codename.

cof/migrations/0009_generic_profiles.py

@@ -30,8 +30,14 @@ def preserve_perms(apps, schema_editor):
     apps.models_module = None
 
     CofProfile = apps.get_model("cof", "CofProfile")
-    memberp = Permission.objects.get(codename='member')
-    burop = Permission.objects.get(codename='buro')
+    memberp = Permission.objects.get(
+        codename='member',
+        content_type__app_label="cof"
+    )
+    burop = Permission.objects.get(
+        codename='buro',
+        content_type__app_label="cof"
+    )
 
     # creates the groups for COF members and
     member = Group.objects.create(name='cof_members')