Fix typo in functional.base
Fix typo in functional.base

Fixes a typo in the functional base class that wasn't updated after
code moved.

Change-Id: Ie9cd7dd1f2b7ffcd80289ecf5da235cfb37e14f3

openstack/akanda-rug,stackforge/akanda-rug,openstack/akanda-rug,stackforge/akanda-rug