Add noreply setting to default docker compose file

[Eevoo]

I had to set this today because out of the box Zulip sends invites as noreply-@smtp.example.com instead of just [email protected], which was causing email bounces as I didn't have a sending identity for that particular email address. The default is true for security reasons as listed in this hack, but I'd argue setting this setting to default to False will be the most pain-free way for most self-hosted users that are only running Zulip and not running it alongside an 'email to public support ticket tracker' feature.

Having said that, even if it is preferred to leave this at True, it will still help smooth the way for self-hosted users to find and change this setting up front rather than needing to track this down and manually create the setting.

[timabbott]

@Eevoo thanks for the report; I don't understand why the emails would have been sent as noreply-@... rather than noreply-{random_token}@... -- did you have a typo in your explanation?

There is certainly an argument for going with the smooth approach rather than the most secure approach, but I want to make sure that there isn't a bug here as well.