debian: disable netfilter-persistent.service

This is now handled by qubes-iptables.service

qubesos/qubes-issues#1067

Makefile

@@ -63,6 +63,9 @@ ifeq ($(shell lsb_release -is), Debian)
     # Wheezy Dropins
     # Disable sysinit 'network-manager.service' since systemd 'NetworkManager.service' is already installed
     DROPINS += $(strip $(if $(filter wheezy, $(shell lsb_release -cs)), network-manager.service,))
+
+	# handled by qubes-iptables service now
+    DROPINS += netfilter-persistent.service
 endif
 
 install-systemd-dropins:

vm-systemd/netfilter-persistent.service.d/30_qubes.conf

@@ -0,0 +1,2 @@
+[Unit]
+ConditionPathExists=/var/run/qubes-service/netfilter-persistent