If you do not set DEFAULT_S3_PATH uploads to S3 silently fail

[NeckBeardPrince]

If you do not set DEFAULT_S3_PATH a double // is added to the S3 path.

silent aws ${PARAM_AWS_ENDPOINT_URL} s3 cp ${temporary_directory}/${backup_job_filename} s3://${backup_job_s3_bucket}/${backup_job_s3_path}/${backup_job_filename}

https://github.com/nfrastack/db-backup/blob/main/rootfs/container/functions/10-dbbackup#L1534-L1537