message: Rename bool method to isEnergyProducer() for consistency
diff: @@ -137,7 +137,7 @@ public:
  bool isWarehouse() const { return structureClass() == StructureClass::Warehouse; }
  bool isRobotCommand() const { return structureClass() == StructureClass::RobotCommand; }
  bool isMineFacility() const { return structureClass() == StructureClass::Mine; }
  - bool energyProducer() const { return structureClass() == StructureClass::EnergyProduction; }
  + bool isEnergyProducer() const { return structureClass() == StructureClass::EnergyProduction; }
  bool isConnector() const { return structureClass() == StructureClass::Tube; }
  bool isRoad() const { return structureClass() == StructureClass::Road; }
  