Add link to upstream ticket in a comment.

roles/fedmsg_base/templates/ssl.py.j2

@@ -137,6 +137,7 @@ config = dict(
         # "cert-prefix" is just "copr", and is hardcoded in
         # backend/dispatcher.py.  The hostname is also a little different,
         # since it is an openstack node.  This might be a little fragile.  :/
+        # See https://github.com/fedora-infra/fedmsg/issues/199 for the plan.
         ("copr.copr-be-i-00000407", "copr-copr-be.cloud.fedoraproject.org"),
     ]),
     routing_policy={