Change openstack-dev to openstack-discuss

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

Change-Id: I7c7fdfb71348f77aa6063ec99b3c4a90bde21d06

Author: sunjia

setup.cfg

@@ -4,7 +4,7 @@ summary = OpenStack Command-line Client
 description-file =
     README.rst
 author = OpenStack
-author-email = openstack-dev@lists.openstack.org
+author-email = openstack-discuss@lists.openstack.org
 home-page = https://docs.openstack.org/python-openstackclient/latest/
 classifier =
     Environment :: OpenStack