Completion helper always with exit-code 1

[Daniel Hahler]

The handler for (Bash) autocompletion exists with code 1 always, which is not helpful in case you want to catch errors, e.g. because some imports failed.

Code reference: ​https://github.com/django/django/blob/bac13074ee5bf6b35e45370fc8b9b14448c765dd/django/core/management/__init__.py#L270

It should exit with 0 by default instead.

It was added in 677ddcbb04, and it does not look like it would be handled / expected by the Bash wrapper, but I have not checked it.