test_rescued_vm_add_remove_security_group missing addCleanup

test_rescued_vm_add_remove_security_group on failure caused
other test cases fail.

Change-Id: I17ebb23f31bc10d669208b64a66e89fa415f96ac
Remove last uses of config without global CONF object

This commit removes that last uses of config without using the global
CONF object.

Partially implements bp config-cleanup

Change-Id: Idc649993b7cd5a45282fde827b2b08f6fb19ab4d
Merge "test_rescued_vm_add_remove_security_group missing addCleanup"
Merge "Remove last uses of config without global CONF object"