Debugger: Fix passing connection when starting from commandline

This fixes a regression when starting debugging from the command line
using 'qtcreator -debug /some/binary,server="localhost:1234"'. The
parameters have been parsed correctly, but were later overwritten
by data from the default (desktop) "device".

Change-Id: I7747eaec6479e55cc18ea21ab1233e89ee9b119a
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Reviewed-by: Eike Ziller <eike.ziller@digia.com>