Hide configuration info for disabled protocol

[JokerQyou]

The webmail uses a standalone configuration file (default.toml), there is this section which controls the configuration info shown in /help page:

[setup]
    # these values are shown in the configuration help page
    [setup.imap]
        hostname="localhost"
        secure=true
        port=9993
    [setup.pop3]
        hostname="localhost"
        secure=true
        port=9995
    [setup.smtp]
        hostname="localhost"
        secure=false
        port=2587

But if POP3 is disabled, the webmail would not know, and still displays those info in /help page.

I would like to suggest adding a disabled key to the [setup.*] section, and hide the corresponding info:

    [setup.pop3]
        disabled=true

[laurivosandi]

Feel free to implement PR with some if statements https://github.com/nodemailer/wildduck-webmail/blob/master/views/help.hbs :)