The method QtServiceBase::setServiceDescription() works only, before the
service is installed. If I call this method after the service is
installed, it has no effect.
Thereby the following problem occurs: The QApplication object is created
after installing the service, during starting it. The QApplication
object is needed to get translations, so I cannot use the QObject::tr()
function to get a translated text to pass through setServiceDescription().

Recommended behavior:
The method QtServiceBase::setServiceDescription() should work at every
time, even if the service is already installed and running. Under
Windows, this behavior can be easily implemented by calling the method
pChangeServiceConfig2() after each call of setServiceDescription().