Can't use NZBGet without a password in new ND version

My setup is all behind a lighttpd password-protected HTTPS reverse proxy, so everything else is set to work without a password - there’s no need to enter a password twice, now is there? - and so far it seemed to be working fine. however, lately, results from my manual searches are not being downloaded. The log has the following error:
Download client isn’t configured yet.
huh? Automatic downloads work just fine and NZBGet is enabled, so what is the problem here? I go into the Settings page, Download Client tab and enter NZBGet configuration and everything is set correctly, with a username but no password. When I try to save:
Invalid request Validation failed:
– ‘Password’ should not be empty.

And if I also remove the username:
Invalid request Validation failed:
– ‘Username’ should not be empty.
– ‘Password’ should not be empty.

Even though it’s a completely valid configuration. Seems to be a regression in one of the latest versions. I’m currently at 2.0.0.1172.

Thanks.

Validation was added recently, I just pushed a change to develop that will only require the password if the username is provided (and vice versa).

Thanks.