Update openstack::swift to support disk storage_type

As the swift::disk patch added in puppet-swift, this patch
update the openstack::swift::storage-node to support disk
storage_type.

Fix bug 1191339

Change-Id: I22e9b565b004ca9be5beb0a843dd4dfd4d29e552
Merge "Update openstack::swift to support disk storage_type"