conf: disallow empty cpuset for emulatorpin
conf: disallow empty cpuset for emulatorpin

It's disallowed in the API.

VenkatDatta/libvirt,nertpinx/libvirt,eskultety/libvirt,nertpinx/libvirt,olafhering/libvirt,libvirt/libvirt,datto/libvirt,olafhering/libvirt,olafhering/libvirt,crobinso/libvirt,eskultety/libvirt,zippy2/libvirt,datto/libvirt,nertpinx/libvirt,eskultety/libvirt,eskultety/libvirt,jfehlig/libvirt,crobinso/libvirt,andreabolognani/libvirt,datto/libvirt,libvirt/libvirt,crobinso/libvirt,eskultety/libvirt,fabianfreyer/libvirt,rlaager/libvirt,jfehlig/libvirt,taget/libvirt,olafhering/libvirt,andreabolognani/libvirt,zippy2/libvirt,crobinso/libvirt,libvirt/libvirt,taget/libvirt,datto/libvirt,fabianfreyer/libvirt,rlaager/libvirt,nertpinx/libvirt,jardasgit/libvirt,jfehlig/libvirt,rlaager/libvirt,taget/libvirt,jardasgit/libvirt,taget/libvirt,taget/libvirt,andreabolognani/libvirt,jardasgit/libvirt,rlaager/libvirt,VenkatDatta/libvirt,jardasgit/libvirt,VenkatDatta/libvirt,jardasgit/libvirt,VenkatDatta/libvirt,nertpinx/libvirt,datto/libvirt,andreabolognani/libvirt,VenkatDatta/libvirt,jfehlig/libvirt,libvirt/libvirt,andreabolognani/libvirt,fabianfreyer/libvirt,zippy2/libvirt,rlaager/libvirt,fabianfreyer/libvirt,zippy2/libvirt,fabianfreyer/libvirt