Change openstack-dev to openstack-discuss
Change openstack-dev to openstack-discuss

Mailinglists have been updated. Openstack-discuss replaces openstack-dev.

Change-Id: Ie473cea777ff3a1707e7e7a69daacf85751996f8

ChameleonCloud/python-blazarclient,stackforge/python-blazarclient,openstack/python-blazarclient