core: fix setting the VM autostart (#925)
core: fix setting the VM autostart (#925)

This is actually workaround for systemd bug reported here:
https://bugzilla.redhat.com/show_bug.cgi?id=1181922

Closes qubesos/qubes-issues#925

marmarek/qubes-core-admin,woju/qubes-core-admin,QubesOS/qubes-core-admin,marmarek/qubes-core-admin,QubesOS/qubes-core-admin,QubesOS/qubes-core-admin,woju/qubes-core-admin,woju/qubes-core-admin,woju/qubes-core-admin,marmarek/qubes-core-admin