Don't invoke the transport if doBackup supplied no data

If there's no data to be backed up, we no longer invoke the transport.  We *DO*
still require that the agent have emitted a valid new state file, however.

This change also finally uncomments the code that removes the backup data file
after it has been sent to the transport, so there will be no more
packagename.data files lying around in the staging area.
1 file changed