fix clientmenu bug where remove last workspace would segfault
fix clientmenu bug where remove last workspace would segfault

Arkq/fluxbox,naimdjon/fluxbox,naimdjon/fluxbox,Arkq/fluxbox,luebking/fluxbox,naimdjon/fluxbox,Arkq/fluxbox,lukoko/fluxbox,Arkq/fluxbox,luebking/fluxbox,lukoko/fluxbox,naimdjon/fluxbox,Arkq/fluxbox,lukoko/fluxbox,olivergondza/fluxbox,luebking/fluxbox,olivergondza/fluxbox,olivergondza/fluxbox,luebking/fluxbox,naimdjon/fluxbox,lukoko/fluxbox,olivergondza/fluxbox,luebking/fluxbox,lukoko/fluxbox,olivergondza/fluxbox