fix bug with None list assignment
fix bug with None list assignment

jdowner/qtile,kopchik/qtile,EndPointCorp/qtile,himaaaatti/qtile,andrewyoung1991/qtile,rxcomm/qtile,aniruddhkanojia/qtile,tych0/qtile,andrewyoung1991/qtile,farebord/qtile,cortesi/qtile,tych0/qtile,flacjacket/qtile,xplv/qtile,kynikos/qtile,kopchik/qtile,kynikos/qtile,farebord/qtile,kseistrup/qtile,frostidaho/qtile,himaaaatti/qtile,kseistrup/qtile,flacjacket/qtile,encukou/qtile,aniruddhkanojia/qtile,cortesi/qtile,apinsard/qtile,EndPointCorp/qtile,ramnes/qtile,de-vri-es/qtile,nxnfufunezn/qtile,ramnes/qtile,soulchainer/qtile,w1ndy/qtile,xplv/qtile,soulchainer/qtile,qtile/qtile,kiniou/qtile,apinsard/qtile,dequis/qtile,w1ndy/qtile,frostidaho/qtile,dequis/qtile,encukou/qtile,zordsdavini/qtile,kiniou/qtile,de-vri-es/qtile,zordsdavini/qtile,StephenBarnes/qtile,nxnfufunezn/qtile,StephenBarnes/qtile,jdowner/qtile,qtile/qtile,rxcomm/qtile