Updated update_launch_config() since flav variable was being set to None.
Updated update_launch_config() since flav variable was being set to None.

briancurtin/pyrax,sivel/pyrax,rackerlabs/heat-pyrax,opsdisk/pyrax,rackspace/pyrax,vikomall/pyrax,ddaeschler/pyrax,0dataloss/pyrax,naemono/pyrax,EdLeafe/pyrax,pratikmallya/pyrax,roelvv/pyrax,mandx/pyrax