https://bugzilla.redhat.com/show_bug.cgi?id=1191227
Since 0fa15b19 we have this variable SYNC_TIME which allows users to
synchronize time on domain resume. However, despite what documentation
says, it's by default on because it's never initialized. Fix this by
setting it to zero at the beginning of the libvirt-guests script.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>