The wireshark-2.4.0 is almost 2 years old now. Assuming anybody
interested in running latest libvirt doesn't run old wireshark,
it is safe to do this. It also simplifies the code.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>