fix regression noted in issue 144
fix regression noted in issue 144

low-sky/pyspeckit,keflavich/pyspeckit,jpinedaf/pyspeckit,allisony/pyspeckit,keflavich/pyspeckit,jpinedaf/pyspeckit,pyspeckit/pyspeckit,vlas-sokolov/pyspeckit,e-koch/pyspeckit,allisony/pyspeckit,e-koch/pyspeckit,vlas-sokolov/pyspeckit,pyspeckit/pyspeckit,low-sky/pyspeckit