Required Area for jets in PAW is showing up as "Need_Area:"

[Clayell]

This should probably be changed to something like "Required Area: (area) m^2"

Relevant function:

SolverEngines/SolverEngines/EngineModule.cs

Lines 106 to 118 in cc88b32

	virtual public void Start()
	{
	CreateEngine();
	Need_Area = RequiredIntakeArea();
	Fields[nameof(Need_Area)].guiActiveEditor = Need_Area > 0f;
	currentThrottle = 0f;
	flameout = false;
	SetUnflameout();
	Fields[nameof(fuelFlowGui)].guiActive = false;
	Fields[nameof(massFlowGui)].guiUnits = " kg/s";
	flowKG = true;
	Fields[nameof(engineTemp)].guiUnits = $" K / {maxEngineTemp:N0} K";
	}

(images from here)