qemu: conf: simplify seccomp_sandbox comment
qemu: conf: simplify seccomp_sandbox comment

It contains too many negations and conditions that are
no longer relevant now that we only support QEMU >= 2.11.

Signed-off-by: Ján Tomko <4cab11cfb98d3c937327354a78eb07dbb6ee2bc6@redhat.com>
Reviewed-by: Michal Privoznik <83d82aaba2eed257f4814b0c239c260c4caaadf0@redhat.com>

nertpinx/libvirt,libvirt/libvirt,zippy2/libvirt,nertpinx/libvirt,nertpinx/libvirt,crobinso/libvirt,zippy2/libvirt,olafhering/libvirt,crobinso/libvirt,nertpinx/libvirt,zippy2/libvirt,jfehlig/libvirt,olafhering/libvirt,zippy2/libvirt,jfehlig/libvirt,jfehlig/libvirt,crobinso/libvirt,nertpinx/libvirt,libvirt/libvirt,libvirt/libvirt,jfehlig/libvirt,olafhering/libvirt,olafhering/libvirt,crobinso/libvirt,libvirt/libvirt