small fix for establishment model admin

apps/establishment/admin.py

@@ -40,6 +40,7 @@ class ContactEmailInline(admin.TabularInline):
 class ReviewInline(GenericTabularInline):
     model = review_models.Review
     extra = 0
+    readonly_fields = ('created_by', 'modified_by')
 
 
 class CommentInline(GenericTabularInline):
@@ -55,7 +56,6 @@ class EstablishmentAdmin(BaseModelAdminMixin):
         AwardInline, ContactPhoneInline, ContactEmailInline,
         ReviewInline, CommentInline]
     raw_id_fields = ('address',)
-    fields = ['old_id', 'name']
 
 
 @admin.register(models.Position)