Remove setting of unnecessary tempest config options

Tempest have removed the volume-feature-enabled.api_v1
config options[1] and modified the default value of
volume-feature-enabled.api_v3 to True.

These config options not needed to be set from devstack
side.

[1] https://review.openstack.org/#/c/573135/

Change-Id: Ic35cf4482ab4d3c2e69348ec92568e68f6ea74ee
1 file changed