Add missing scene clear on LoadEmptyContent
Add missing scene clear on LoadEmptyContent

- Issue MatterHackers/MCCentral#4250
Clear bed is no longer working

jlewin/MatterControl,mmoening/MatterControl,larsbrubaker/MatterControl,jlewin/MatterControl,larsbrubaker/MatterControl,larsbrubaker/MatterControl,unlimitedbacon/MatterControl,mmoening/MatterControl,unlimitedbacon/MatterControl,jlewin/MatterControl,larsbrubaker/MatterControl,jlewin/MatterControl,unlimitedbacon/MatterControl,unlimitedbacon/MatterControl,mmoening/MatterControl