Fix double accounting for unit conversion

mission_analysis/src/standard_mission/fuel_handling/fuel_handling.cpp

@@ -298,8 +298,7 @@ double standard_mission::calculate_holding_fuel(const double& aircraft_mass, con
         EndnodeReadOnly<int>("energy_carrier_ID").read(rtIO->acxml.at("requirements_and_specifications/design_specification/propulsion/energy_provider/descent")).value();
     atmosphere holding_atm; //Airbus defines to calculate holding pattern at ISA-Conditions
     double holding_mach(EndnodeReadOnly<double>("/program_settings/general/fuel_planning/holding/holding_mach_number").read(this->rtIO->moduleConfig).value());
-    double holding_altitude(convertUnit(FOOT, METER,
-        EndnodeReadOnly<double>("/program_settings/general/fuel_planning/holding/holding_altitude").read(this->rtIO->moduleConfig).value()));
+    double holding_altitude(EndnodeReadOnly<double>("/program_settings/general/fuel_planning/holding/holding_altitude").read(this->rtIO->moduleConfig).value());
     if (EndnodeReadOnly<bool>("program_settings/general/fuel_planning/holding/use_economical_speed").read(this->rtIO->moduleConfig).value()) {
         this->calculate_econ_cruise_speed(&holding_mach, holding_altitude, 0., aircraft_mass, this->aero.cruiseConfiguration, "cruise");
     }