Updated openstack/openstack
Project: openstack/nova  12c5f644b7bb966c5f035204c92ef44e4c611a90
null
Make _change_index_columns use existing utility methods

The _change_index_columns method is doing a drop/add index operation and
since we have utility methods to do exactly that already, just re-use
them.

Change-Id: I5706c4512b1324aab64f70cd053c464d9a50e233