How to delete "proxy" attribute in passdb lookup?

[Timo Sirainen]

On 29 Nov 2015, at 19:00, Peer Heinlein <p.heinlein at heinlein-support.de> wrote:
> 
>> It would probably also be useful to add support for removing a
>> field entirely, such as returning "-proxy" (where the =value would
>> be ignored). I'm not entirely sure how useful that would be
>> though.
> 
> Why don't just enable
> 
> override_fields = proxy=
> 
> so, just use "attribue=<nothing>" to delete it?

There could be some settings which are wanted to be explicitly cleared. For example in dovecot.conf have "mail_plugins=foo" while in passdb it could be disabled with "mail_plugins=". There are probably some better examples.