error from dandi ls without -r option

Don't understand why I have error when using `dandi ls sub-RAT123/` (on dandiset `000027`), at the same time the command runs fine with `dandi ls -r sub-RAT123/`. Since `sub-RAT123` has only one file I would expect that the command without `-r` should be sufficient.

```
(dandicli_dev_py39) MacBook-Pro-2:000027 dorota$ ls -l sub-RAT123/
total 40
-rw-r--r-- 1 dorota staff 18792 Oct 21 2020 sub-RAT123.nwb
(dandicli_dev_py39) MacBook-Pro-2:000027 dorota$
(dandicli_dev_py39) MacBook-Pro-2:000027 dorota$ dandi ls sub-RAT123/
2022-10-04 16:06:48,825 [ WARNING] A newer version (0.46.3) of dandi/dandi-cli is available. You are using 0.14.2+1335.ge021829
- errors: 1
path: sub-RAT123/
2022-10-04 16:06:49,792 [ WARNING] Failed to operate on some paths (empty records were listed):
AttributeError: 1 paths
2022-10-04 16:06:49,792 [ INFO] Logs saved in /Users/dorota/Library/Logs/dandi-cli/20221004200648Z-90443.log
(dandicli_dev_py39) MacBook-Pro-2:000027 dorota$
(dandicli_dev_py39) MacBook-Pro-2:000027 dorota$
(dandicli_dev_py39) MacBook-Pro-2:000027 dorota$ dandi ls -r sub-RAT123/
2022-10-04 16:06:59,711 [ WARNING] A newer version (0.46.3) of dandi/dandi-cli is available. You are using 0.14.2+1335.ge021829
PATH SEX IDENTIFIER SUBJECT_ID SESSION_START_TIME SPECIES NWB ND_TYPES AGE GENOTYPE SESSION_DESCRIPTION SIZE
sub-RAT123/
sub-RAT123/sub-RAT123.nwb M TEST_Subject RAT123 1971-01-01/12:00:00 Rattus norvegicus 2.0b Subject 12 mo WT a file to test writing and reading a Subject 18.8 kB
Summary: 1971-01-01/12:00:00> 18.8 kB
1971-01-01/12:00:00<
2022-10-04 16:07:00,647 [ INFO] Logs saved in /Users/dorota/Library/Logs/dandi-cli/20221004200659Z-90460.log
```