Galera cluster: SST should leave old binary logs alone

When a joiner node requests an SST, its data dir is wiped out in preparation for xtrabackup/mariabackup. I have observed that now the script also deletes all binlog files if present, even if they are in another folder.

I feel that the existing binlogs should be left alone, as they may be useful eg. in troubleshooting issues in the cluster. Please, do not delete them.

Thank you
Rick