require acceleration curve to be valid (case then .vacc file is not valid is...

require acceleration curve to be valid (case then .vacc file is not valid is handled in the cach-block

VectoCore/VectoCore/InputData/FileIO/JSON/JSONInputData.cs

@@ -480,7 +480,7 @@ namespace TUGraz.VectoCore.InputData.FileIO.JSON
 //					throw new VectoException("AccelerationCurve (VACC) required");
 				}
 				try {
-					return ReadTableData(acceleration.Value<string>(), "DriverAccelerationCurve", false);
+					return ReadTableData(acceleration.Value<string>(), "DriverAccelerationCurve", true);
 				} catch (VectoException e) {
 					Log.Warn("Could not find file for acceleration curve. Trying lookup in declaration data.");
 					try {