Revert upgrading of cinder-rootwrap config

Commit 388c5382cfa099a4bfb096ce66f9473f76a86f48 added the refresh of
cinder-rootwrap config on upgrade from havana to icehouse.

However, the final model used for migration to oslo.rootwrap is seamless
and does not require changes in cinder configuration, so this is
actually useless.

Change-Id: I4a629ba3b83f2518b5033899c5aa1180be471e34
Merge "Revert upgrading of cinder-rootwrap config"