qubes-anaconda-addon: Disable libvirt-guests service

This service suspends virtual machines at shutdown time and resumes them
at start-up time. This unfortunately breaks virtual machines which have
PCI devices attached.

qubes-anaconda-addon/firstboot-qubes-text

@@ -91,7 +91,7 @@ done
 
 set -e
 
-for service in rdisc kdump; do
+for service in rdisc kdump libvirt-guests; do
     systemctl disable ${service}.service || :
     systemctl stop    ${service}.service || :
 done

qubes-anaconda-addon/org_qubes_os_initial_setup/gui/spokes/qubes_os.py

@@ -484,7 +484,7 @@ class QubesOsSpoke(FirstbootOnlySpokeMixIn, NormalSpoke):
     def configure_dom0(self):
         self.set_stage("Setting up administration VM (dom0)")
 
-        for service in [ 'rdisc', 'kdump' ]:
+        for service in [ 'rdisc', 'kdump', 'libvirt-guests' ]:
             self.run_command(['systemctl', 'disable', '{}.service'.format(service) ], ignore_failure=True)
             self.run_command(['systemctl', 'stop',    '{}.service'.format(service) ], ignore_failure=True)