Do not use rsync when moving .tar.gz files from workspace to user account

Currently if you use the "generate download link" feature in Jetbackup, Jetbackup will transfer the file using rsync from backup server to local machine, tar it up - then rsync the file from /home/.jbm/workspace/downloads/<name>.tar.gz to /home/$username/.jbm/downloads/<name>.tar.gz

In the last step it's advised to not use rsync since you'll read the full file, to then write it again.

You could simply "mv" the file, in most cases this would be instant, since you're just updating the location, but not actually writing any data (greatly speeds up for large accounts).

Also the rm -rf /home/.jbm/workspace/downloads command that runs afterwards doesn't use `ionice` or `nice` commands, so they'll eat the IO during deletion as well.