close JSON parser after deserialization

src/main/jastadd/Backend.jadd

@@ -1212,6 +1212,7 @@ aspect Serializer {
     sb.append(ind(3) + "com.fasterxml.jackson.core.JsonFactory factory = mapper.getFactory();\n");
     sb.append(ind(3) + "com.fasterxml.jackson.core.JsonParser parser = factory.createParser(file);\n");
     sb.append(ind(3) + getID() + " result = deserialize((com.fasterxml.jackson.databind.JsonNode)mapper.readTree(parser));\n");
+    sb.append(ind(3) + "parser.close();\n");
     sb.append(ind(3) + "return result;\n");
     sb.append(ind(2) + "} catch (java.io.IOException e) {\n");
     sb.append(ind(3) + "throw new DeserializationException(\"unable to deserialize \" + file.getAbsolutePath(), e);\n");