Remove unused JSSourceValue::setAlternatives
Remove unused JSSourceValue::setAlternatives

Change-Id: Ia91cf8b93f6d1bcb3d526d13c4e48e2662205232
Reviewed-by: Christian Kandeler <3aa99dcdd3f0cac61fb81c2a11771c0cc2497607@qt.io>
Reviewed-by: Jake Petroules <2d627e1cecd5435752fa500bacbe05f7cc90c369@qt.io>

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