Fixed Minor bug
Fixed Minor bug

- Closing fluxgui during first-time setup would throw an exception
  and user would be unable to close fluxgui. Also handles if xflux
  crashes for some reason.

adrian-castravete/f.lux-indicator-applet,Kilian/f.lux-indicator-applet,xflux-gui/xflux-gui,esmail/f.lux-indicator-applet,studio666/f.lux-indicator-applet,TyrusChin/f.lux-indicator-applet,bitzl/f.lux-indicator-applet,NHellFire/f.lux-indicator-applet