Fix the branch point for mistral-lib

The stable/pike branch for mistral-lib was created at 0.2.0 but in
I0a8bb59c35aec40ae529fce5da6f30f3820991af, I mistakenly approved the
change to switch that to 0.3.0.

Set it back to the correct branch point

Change-Id: I34e053831eba3d015566242bc91894da6c27ff8f

deliverables/pike/mistral-lib.yaml

@@ -31,6 +31,6 @@ releases:
         hash: 8986ce9529f90ed5cdb52fd54a54ccc21378b320
 branches:
   - name: stable/pike
-    location: 0.3.0
+    location: 0.2.0
 repository-settings:
   openstack/mistral-lib: {}