liveboot_rsync: don't use archive option for rsync

liveboot_rsync: don't use archive option for rsync

liveboot_rsync facilitates rsync module whileas dcmanager uses
a dedicated user to sync files via SSH. this causes rsync daemon
on mgmt1 to reset permissions in such a way that dcmanager isn't
capable of resetting the mtime value of "." (parent directory of
destination) and hence throws error in UI. dcmanager doesn't use
the same rsync options (yet), which could make sense to have both
sources operating the same way.