Update reno for removed network CLIs

We still support the add/remove fixed IP commands for
nova-network (the multinic API which isn't deprecated yet),
so this updates the release notes to clarify that.

Change-Id: Ib3468b93e2b396fa1372d3df4be4454f8bc64314

releasenotes/notes/pike-rm-deprecated-net-272aeb62b329a5bc.yaml

@@ -2,8 +2,8 @@
 prelude: >
     Deprecated network-related resource commands and python API bindings
     have been removed. From this point on, python-novaclient will no longer
-    work with nova-network *except* for the ``nova virtual-interface-list``
-    command.
+    work with nova-network *except* for the ``nova virtual-interface-list``,
+    ``nova add-fixed-ip`` and ``nova remove-fixed-ip`` commands.
 upgrade:
   - |
     The following deprecated network-related resource commands have been