[C++] Bugfix in LibjoynrSettings.cpp
[C++] Bugfix in LibjoynrSettings.cpp

invoke correct setters with default values in case the incoming setting
values have not the required values.

Change-Id: Iadd188840aaf5fb632363ee0580db7f7619e9392

clive-jevons/joynr,bmwcarit/joynr,clive-jevons/joynr,clive-jevons/joynr,bmwcarit/joynr,bmwcarit/joynr,clive-jevons/joynr,bmwcarit/joynr,clive-jevons/joynr,bmwcarit/joynr,bmwcarit/joynr,bmwcarit/joynr,bmwcarit/joynr,clive-jevons/joynr,bmwcarit/joynr