This option was originally added in d05aa418b0,
and moved in 8b15839ee8 (after which it temporarily
went to the docker/engine-api repository, and was brought back in this repository
in 91e197d614).
However, it looks like this field was never used; the API always returns the standard
information, and the "--quiet" option for `docker ps` is implemented on the CLI
side, which uses different formatting when setting this option;
2ec468e284/api/client/ps.go (L73-L79)
This patch removes the unused field,
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
4d3f64da63