The custom namespaces were originally registered against the storage
pool source struct, but during review this was changed to the top level
storage pool struct. The namespace URIs were not updated to match, so
had a redundant '/source' component.
Reviewed-by: NJohn Ferlan <jferlan@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>