sending delta differences on each run

Hi,

This is a question/improvement.

After being using for while btrbk I am happy with the balance between complexity of configuration and results (thanks for taking your time to develop it). However, there is something that is getting me crazy when I run the backups (or maybe my peanut brain is not able to understand).

I have defined the following btrbk.conf file with the shared keys between this host and the NAS:

```
snapshot_preserve_min 1d
snapshot_preserve 5d

target_preserve_min no
target_preserve 10d 10w *m

archive_preserve_min latest
archive_preserve 12m 10y

volume /mnt/btr_data
snapshot_create always
target send-receive ssh://10.0.2.150/dataready/Backup/
subvolume @
subvolume @home
```

Also a cron job on daily basis.

However, if I manually run the backup (after the daily cron) it does not transfer anything to remote, and it is only creating a local snapshot.

Is there a way of sending the delta differences after each run instead of only one time per day? (i.e: deleting the remote backup and create a new one).

I have to manually delete in local and remote all the backups/snapshots belonging to that day, and then run it again in order to have the remote storage updated.

Thanks in advance.