commit 15a37d5ef6e3859591d07a01607a93638f5ec8b3
Author: Daniel Watkins <daniel.watkins@canonical.com>
Date:   Fri Oct 7 11:33:48 2016 +0100

    systemd: Run cloud-init.service Before dbus.socket not dbus.target
    
    The change reported to fix bug 1629797 was incorrect.  It added:
      Before=dbus.target
    dbus.target does not exist, so the change did not fix the problem or
    actually make any difference.
    
    The fix here is just to use Before=dbus.socket.
    
    LP: #1629797