hopefully fix bad backup

Dockerfile

@@ -43,7 +43,7 @@ COPY --from=builder /pause/pauser /pauser
 USER root
 ### CRON BACKUPS
 RUN true \
-   && echo 'b=$(date +%Y%m%d%H%M%S); mkdir -p /mnt/save/$b; pg_dump $DATABASE_URL --clean > /mnt/save/$b/pg.dump || (rm -rf /mnt/save/$b; echo "backup failed; deleting $b"; exit 1); exit $?' > /backup.sh \
+   && echo 'b=$(date +%Y%m%d%H%M%S); mkdir -p /mnt/save/$b; pg_dump $DATABASE_URL --clean > /mnt/save/$b/pg.dump || (rm -rf /mnt/save/$b; echo "backup failed; deleting $b"; exit 1); if du -sh /mnt/save/$b | grep -i "^[ ]*4.0K"; then rm -rf /mnt/save/$b; echo rm empty backup $b; fi' > /backup.sh \
    && echo 'b=$(find /mnt/save -type f | sort | tail -n 1); if [ -n "$b" ]; then echo restoring $b; psql $DATABASE_URL < "$b"; fi && service postgresql start;' > /restore.sh \
    && echo '0 4,8,12,16,20 * * * bash /backup.sh >> /var/log/cronj.log 2>&1' > /etc/cron.d/backups \
    && echo '' >> /etc/cron.d/backups \