qemu: hotplug: Remove wrong check for empty disks
qemu: hotplug: Remove wrong check for empty disks

The check if the disk is empty is wrong and would spuriously reject NBD
sources. Remove it.

zippy2/libvirt,eskultety/libvirt,eskultety/libvirt,crobinso/libvirt,jfehlig/libvirt,andreabolognani/libvirt,fabianfreyer/libvirt,fabianfreyer/libvirt,olafhering/libvirt,jardasgit/libvirt,zippy2/libvirt,libvirt/libvirt,andreabolognani/libvirt,eskultety/libvirt,crobinso/libvirt,libvirt/libvirt,andreabolognani/libvirt,olafhering/libvirt,zippy2/libvirt,nertpinx/libvirt,jardasgit/libvirt,fabianfreyer/libvirt,nertpinx/libvirt,jfehlig/libvirt,fabianfreyer/libvirt,jardasgit/libvirt,nertpinx/libvirt,olafhering/libvirt,andreabolognani/libvirt,olafhering/libvirt,crobinso/libvirt,crobinso/libvirt,libvirt/libvirt,jardasgit/libvirt,nertpinx/libvirt,jfehlig/libvirt,zippy2/libvirt,eskultety/libvirt,jardasgit/libvirt,nertpinx/libvirt,fabianfreyer/libvirt,jfehlig/libvirt,libvirt/libvirt,eskultety/libvirt,andreabolognani/libvirt