tests: add a domain ID to live status XML doc

The status XML represents a running VM, so we should always have an
ID present for the domain.
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

tests/qemustatusxml2xmldata/vcpus-multi-in.xml

@@ -310,7 +310,7 @@
   <allowReboot value='yes'/>
   <blockjobs active='no'/>
   <agentTimeout>-2</agentTimeout>
-  <domain type='kvm'>
+  <domain type='kvm' id='1729'>
     <name>QEMUGuest1</name>
     <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
     <memory unit='KiB'>219100</memory>