solved: JSP fails to set dev't PORT explicitly, which breaks 'real email' urls if using `foreman start`

If you send mails in development, this does not work if you use `foreman start` to start your app:
```
# environment/development.rb (default port handling)
  config.action_mailer.default_url_options = {host: "lvh.me", port: ENV.fetch("PORT", 3000).to_i}
```

The web PORT is 5000.

The worker PORT is 5200 (foreman bumps the PORT for each process up by 100).

So mail urls point to 5200, not 5000, if an email is sent via worker.

I use the dotenv-rails gem, and my .env.development file has MAILER_PORT=5000 and my initializer uses {host: "lvh.me", port: ENV.fetch("MAILER_PORT", 5000).to_i}