QtIFW

Use written localhost address, adapt code.

Use the default address throughout the whole code. Instead of
relying on the QHostAddress::SpecialAddress enum, use the full
qualified and more descriptive address of localhost.

Change-Id: I64b3459245682532f84306703e29ac276d4e468d
Reviewed-by: Kai Koehne <kai.koehne@theqtcompany.com>