Release magnum RC2 for Train

This release is being proposed to pick up translations and bugfixes
that have merged to stable/train but not been released.

Not all changes are critical to make it into the initial Train
coordinated release and can wait until a stable release later. If
this patch does not get an ack from the PTL and/or release liaison
by EOD Thursday it will just be abandoned.

Teams may also choose to -1 this patch and update it once any final
commits merge prior to the October 10 deadline.

Change-Id: I48adba327b23f59b5e77c9d4e7df9fba05b45933

deliverables/train/magnum.yaml

@@ -10,6 +10,10 @@ releases:
     projects:
       - repo: openstack/magnum
         hash: a0c894a222a08600edf612f48fad628758b48dbf
+  - version: 9.0.0.0rc2
+    projects:
+      - repo: openstack/magnum
+        hash: 5e66b4fe637e56f2719edae6e21aab354792bb30
 branches:
   - name: stable/train
     location: 9.0.0.0rc1