do not create radosgw region map in post-deploy

RadosGW region map may intermittently get corrupted when it is created
during post-deployment, leading to RadosGW being unable to start.

Change-Id: I9587b983ad50d74d22eb157b5d98a6f709e58b23
Related-bug: #1287166
Merge "do not create radosgw region map in post-deploy"