Fix duplicated rootwrap.d in lib/ironic

The Ironic setup of devstack is duplicating the rootwrap.d directory at
/etc/ironic/rootwrap.d/rootwrap.d, this will cause the ironic-rootwrap
command to fail to execute. This patch is removing the duplicated
rootwrap.d directory.

Change-Id: I24844c24620b5b33ad1a6acd0d872e9df11d6d89
Closes-Bug: #1268930
Merge "Fix duplicated rootwrap.d in lib/ironic"