SimpleListFilter is a property of admin not gis.admin

gazetteer/places/admin.py

@@ -1,7 +1,7 @@
 from django.contrib.gis import admin
 from models import *
 from django import forms
-
+from django.contrib.admin import SimpleListFilter
 
 class FeatureTypeFilter(admin.SimpleListFilter):
     # Human-readable title which will be displayed in the