Update references with new Mailing List location
Update references with new Mailing List location

Yesterday, openstack@lists.launchpad.org was migrated with
all users to openstack@list.openstack.org.

This patch updates references to the old mailing list with the
new, to ensure that people encountering them don't accidentally
try and join the old list!

Change-Id: I59c6268637dea8ca06cdb8bf28808d1b59562ff7

openstack/openstack-manuals,openstack/openstack-manuals,saeki-masaki/openstack-manuals,potsmaster/openstack-manuals,kairoaraujo/openstack-manuals,potsmaster/openstack-manuals,AlekhyaMallina-Vedams/openstack-manuals,gongysh2004/openstack-manual,Akasurde/openstack-manuals,kairoaraujo/openstack-manuals,AlekhyaMallina-Vedams/openstack-manuals,openstack/openstack-manuals,saeki-masaki/openstack-manuals,gongysh2004/openstack-manual,Akasurde/openstack-manuals,AlekhyaMallina-Vedams/openstack-manuals,openstack/openstack-manuals