Default region loading an old-style pickled ring

This is to support upgrades from swift < 1.8 using old-style pickled
rings to 1.10. Old-style pickled rings won't have region information.

Change-Id: I18b2acba3d346e41def9d25d3d4dbd12705e5375
Closes-Bug: #1248919
Merge "Default region loading an old-style pickled ring"