Fixed nullref in delegate creation of non-public fields

Author: alelievr

Assets/com.alelievr.NodeGraphProcessor/Runtime/Elements/NodePort.cs

@@ -169,8 +169,8 @@ PushDataDelegate CreatePushDataDelegateForEdge(SerializableEdge edge)
 			try
 			{
 				//Creation of the delegate to move the data from the input node to the output node:
-				FieldInfo inputField = edge.inputNode.GetType().GetField(edge.inputFieldName, BindingFlags.Public | BindingFlags.Instance);
-				FieldInfo outputField = edge.outputNode.GetType().GetField(edge.outputFieldName, BindingFlags.Public | BindingFlags.Instance);
+				FieldInfo inputField = edge.inputNode.GetType().GetField(edge.inputFieldName, BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance);
+				FieldInfo outputField = edge.outputNode.GetType().GetField(edge.outputFieldName, BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance);
 				Type inType, outType;
 
 #if DEBUG_LAMBDA