Added dummy member GetPriceSteps().

To implement in a later step.

library/src/calculator_functions.cpp

@@ -695,6 +695,10 @@ Ticket Calculator::private_GetDurationFromCost(Configuration *cfg,
                cost, Ticket::s[VALID]);
 }
 
+QList<int> Calculator::GetPriceSteps(Configuration * /*cfg*/) const {
+    return QList<int>();
+}
+
 QList<int> Calculator::GetTimeSteps(Configuration *cfg) const {
     if (m_timeSteps.size() > 0) {
         //qCritical() << __PRETTY_FUNCTION__ << "timeSteps:" << m_timeSteps;