users: Creating LDAP user failed

Reported by Danrancan at https://discuss.freedombox.org/t/creating-ldap-user-failed-message-after-clean-install-and-creating-new-user-and-password/1273 :

I do a fresh install of Freedombox pioneer edition (Latest weekly image) with the dd command. Then, I insert sd card and wait for boot. Then, upon entering my new username and password after it asks me to, I get the following error message:

Creating LDAP user failed: ('users', '', 'No such object (32)\nMatched DN: ou=groups,dc=thisbox\nTraceback (most recent call last):\n File "/usr/share/plinth/actions/users", line 583, in \n main()\n File "/usr/share/plinth/actions/users", line 579, in main\n subcommand_method(arguments)\n File "/usr/share/plinth/actions/users", line 315, in subcommand_create_user\n set_samba_user(username, password)\n File "/usr/share/plinth/actions/users", line 372, in set_samba_user\n timeout=10)\n File "/usr/lib/python3.7/subprocess.py", line 939, in communicate\n stdout, stderr = self._communicate(input, endtime, timeout)\n File "/usr/lib/python3.7/subprocess.py", line 1682, in _communicate\n self._check_timeout(endtime, orig_timeout)\n File "/usr/lib/python3.7/subprocess.py", line 982, in _check_timeout\n raise TimeoutExpired(self.args, orig_timeout)\nsubprocess.TimeoutExpired: Command '['smbpasswd', '-a', '-s', 'ShinaniGunz22x']' timed out after 10 seconds\n')