We currently only have a single process binary for Qt.
Therefore we should not choose a different binary based on required privileges.
However, this patch can only be a preliminary solution.
May be we should instead implement our own ChildProcessHost.

Change-Id: I0e76ff44f474842c7a96317a05f9964782f68080
Reviewed-by: Andras Becsi <andras.becsi@digia.com>