Don't throw exceptions from EvaluatorScriptClass.
Don't throw exceptions from EvaluatorScriptClass.

Task-number: QBS-863
Change-Id: I4fcd08fcd8c055bb12afe28a344f00f3b2cfe9c1
Reviewed-by: Joerg Bornemann <47777b9406dbddd02a3fdca8341789a013805a11@theqtcompany.com>

qtproject/qt-labs-qbs,qt-labs/qbs,qt-labs/qbs,qt-labs/qbs,qt-labs/qbs,gatzka/qt-labs-qbs,qtproject/qt-labs-qbs,gatzka/qt-labs-qbs,gatzka/qt-labs-qbs,qt-labs/qbs,gatzka/qt-labs-qbs,qt-labs/qbs,qtproject/qt-labs-qbs,qtproject/qt-labs-qbs,gatzka/qt-labs-qbs,gatzka/qt-labs-qbs,qtproject/qt-labs-qbs,qt-labs/qbs,gatzka/qt-labs-qbs,qtproject/qt-labs-qbs,qtproject/qt-labs-qbs