Fix typo in the external service loader code
Fix typo in the external service loader code

Change-Id: I57b4c6747688df229194622645265832f07bea20

openstack/python-openstacksdk,openstack/python-openstacksdk,stackforge/python-openstacksdk,dtroyer/python-openstacksdk,stackforge/python-openstacksdk,dtroyer/python-openstacksdk