Misleading error message when no app id and token is supplied for nokia plugin

Steps to reproduce:
1) run the qml_location_mapviewer example without providing any parameters
2) observe the error messages mentioning that Plugin does not support ____.
This is confusing for the developer as the plugin does support the functionality and it is simply the authentication parameters that are incorrect.

A similar problem has been addressed for places at:
https://codereview.qt-project.org/#change,30983

qrc:///content/map/MapComponent.qml:214:37: QML RouteModel: Error: Plugin does not support routing.
Error message: Qt Location requires app_id and token parameters.
Please register at https://api.developer.nokia.com/ to get your personal application credentials.
qrc:///content/map/MapComponent.qml:248:41: QML GeocodeModel: Error: Plugin does not support (reverse) geocoding.
Error message: Qt Location requires app_id and token parameters.
Please register at https://api.developer.nokia.com/ to get your personal application credentials.
qrc:///mapviewer.qml:269:9: QML GeocodeModel: Error: Plugin does not support (reverse) geocoding.
Error message: Qt Location requires app_id and token parameters.
Please register at https://api.developer.nokia.com/ to get your personal application credentials.
qrc:///inline:1:122: QML MapComponent: Error: Plugin does not support mapping.
Error message: Qt Location requires app_id and token parameters.
Please register at https://api.developer.nokia.com/ to get your personal application credentials.
QObject::connect: Cannot connect (null)::copyrightsChanged(const QImage &, const QPoint &) to QDeclarativeGeoMapCopyrightNotice::copyrightsChanged(const QImage &, const QPoint &)