server.Initialize receive an unnecessary argument

[joselsegura]

(copied from RedHatInsights/insights-results-aggregator#847)

The method server.Initialize has one string argument containing an address. This argument is only used to print a log message.

This log message is more or less the same as the one printed in server.Start, and the address that currently is taken from the argument can be safely extracted from server.Configuration.Address instead.