Fixed producer fallback in sandbox mode

[ramunasd]

Fallback lacks method setContentType

[videlalvaro]

The tests are not passing.

Also, wouldn't this break BC?

[ramunasd]

Travis had temporary issue, now it's passing all tests.
About BC - if someone has written it's own producer that implements ProducerInterface - then yes, it BC.

[videlalvaro]

Sorry to comment so late, but I think this method and setDeliveryMode should be added here as well? Why not have them in the ProducerInterface as well?

[github-actions]

This pull request has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[ramunasd]

@mihaileu this is the old one, but maybe still actual?

[mihaileu]

As is a BC, it should be added in the next major version.