don't set security groups in 'instance create' opts if no flag given
don't set security groups in 'instance create' opts if no flag given

brint/rack,nelsnelson/rack,dolph/rack,nelsnelson/rack,rackspace/rack,ryanvz/rack,dolph/rack,jarosser06/rack,rackspace/rack,annegentle/rack,brint/rack,jarosser06/rack,pratikmallya/rack,DonNateR/rack,annegentle/rack,DonNateR/rack,jrperritt/rack,pratikmallya/rack,ryanvz/rack,jrperritt/rack