Remove nova v2 API comments
Remove nova v2 API comments

The removed comments were for distinguishing them from nova v3 API
but now the v3 API has been removed.
So these comments are meaningless, then this patch removes them.

Change-Id: Icb51ddafcf2c06f5400f572a0862e5f67ee4dfc5

bigswitch/tempest,Tesora/tesora-tempest,rakeshmi/tempest,izadorozhna/tempest,rakeshmi/tempest,zsoltdudas/lis-tempest,cisco-openstack/tempest,cisco-openstack/tempest,vedujoshi/tempest,vedujoshi/tempest,izadorozhna/tempest,LIS/lis-tempest,tonyli71/tempest,openstack/tempest,bigswitch/tempest,Juniper/tempest,tonyli71/tempest,LIS/lis-tempest,Tesora/tesora-tempest,openstack/tempest,xbezdick/tempest,zsoltdudas/lis-tempest,Juniper/tempest,masayukig/tempest,sebrandon1/tempest,masayukig/tempest,sebrandon1/tempest,xbezdick/tempest