Fix sample configuration generation for compute-related options
Fix sample configuration generation for compute-related options

Currently the compute_opts are duplicated in both [DEFAULT] and [compute]
sections, while compute_group_opts are missing at all.

This patch does not affect where the options actually are, only where
they are displayed in the sample configuration.

Closes-Bug: #1712855

Change-Id: I68f246998fd68e669b0d9ef34b00ed384f4f0c90

rahulunair/nova,mikalstill/nova,mikalstill/nova,klmitch/nova,openstack/nova,klmitch/nova,gooddata/openstack-nova,klmitch/nova,openstack/nova,gooddata/openstack-nova,mahak/nova,rahulunair/nova,openstack/nova,phenoxim/nova,gooddata/openstack-nova,gooddata/openstack-nova,mikalstill/nova,phenoxim/nova,mahak/nova,mahak/nova,klmitch/nova,rahulunair/nova