Remove redundant variables from context class
Remove redundant variables from context class

This cleans up the context class by removing variables that are already
avialable from oslo.context.

Change-Id: Ib102eb372d347d3d91c6ceca43889f5edc33e6be

openstack/keystone,mahak/keystone,openstack/keystone,mahak/keystone,openstack/keystone,mahak/keystone