fx: fix bug where setting shader param to 0 would be ignored

hrt/prefab/fx/BaseFX.hx

@@ -137,10 +137,7 @@ class BaseFX extends hrt.prefab.Library {
 					var curve = Curve.getCurve(shaderElt, v.name);
 					var val = Value.VConst(base);
 					if(curve != null)
-						if (base != 0.0)
-							val = Value.VCurveScale(curve, base);
-						else
-							val = Value.VCurve(curve);
+						val = Value.VCurveScale(curve, base);
 					ret.push({
 						def: v,
 						value: val