apparmor, libvirt-qemu: qemu won't call qemu-nbd

While libvirtd might do so, qemu itself as a guest will not need
to call qemu-nbd so remove it from the profile.
Signed-off-by: NChristian Ehrhardt <christian.ehrhardt@canonical.com>
Signed-off-by: NStefan Bader <stefan.bader@canonical.com>

examples/apparmor/libvirt-qemu

@@ -141,7 +141,6 @@
   /usr/bin/qemu-mipsel rmix,
   /usr/bin/qemu-mipsn32 rmix,
   /usr/bin/qemu-mipsn32el rmix,
-  /usr/bin/qemu-nbd rmix,
   /usr/bin/qemu-or32 rmix,
   /usr/bin/qemu-ppc rmix,
   /usr/bin/qemu-ppc64 rmix,