Add prompt for SMTP server and port to internal-init.php

[rjl]

The internal-init.php script is designed to gather basic information required to bootstrap an internal authentication database, so that the superadmin can receive his temporary credentials to login. The downstream MTA host and port number is not being gathered, however, so the default of localhost:10025 is being used. Users with non-typical scenarios need to be able to change these values, so internal-init.php should add prompts for this information.

[dmorton]

fixed in [551]