Fix the os-extended-volumes key reference in the REST API history docs
Fix the os-extended-volumes key reference in the REST API history docs

The actual key in the response is os-extended-volumes:volumes_attached
so the REST API history doc needs to be updated for v2.3.

Change-Id: I17e8ddaf939718f737b3098357938ecd647e872c
Closes-Bug: #1511094

bigswitch/nova,Juniper/nova,dims/nova,bigswitch/nova,BeyondTheClouds/nova,sebrandon1/nova,jianghuaw/nova,NeCTAR-RC/nova,zhimin711/nova,apporc/nova,dims/nova,hanlind/nova,cyx1231st/nova,BeyondTheClouds/nova,apporc/nova,Juniper/nova,alaski/nova,rahulunair/nova,gooddata/openstack-nova,vmturbo/nova,cernops/nova,mahak/nova,zhimin711/nova,gooddata/openstack-nova,rahulunair/nova,sebrandon1/nova,Juniper/nova,BeyondTheClouds/nova,openstack/nova,rajalokan/nova,cloudbase/nova,mahak/nova,klmitch/nova,cernops/nova,vmturbo/nova,mahak/nova,jianghuaw/nova,openstack/nova,cloudbase/nova,rajalokan/nova,CEG-FYP-OpenStack/scheduler,Juniper/nova,gooddata/openstack-nova,rajalokan/nova,rahulunair/nova,hanlind/nova,CEG-FYP-OpenStack/scheduler,hanlind/nova,jianghuaw/nova,mikalstill/nova,NeCTAR-RC/nova,vmturbo/nova,openstack/nova,klmitch/nova,rajalokan/nova,phenoxim/nova,klmitch/nova,cernops/nova,gooddata/openstack-nova,cyx1231st/nova,alaski/nova,klmitch/nova,mikalstill/nova,phenoxim/nova,mikalstill/nova,jianghuaw/nova,sebrandon1/nova,cloudbase/nova,vmturbo/nova