device: use the real communication mode of the device when writing a packet

If the device is remote and its mode is not known, the packet was always
being written as in API mode, but it must be written using the mode of the
local device.

Signed-off-by: Ruben Moral <ruben.moral@digi.com>

Author: rubenmoral

library/src/main/java/com/digi/xbee/api/AbstractXBeeDevice.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2019, Digi International Inc.
+ * Copyright 2017-2022, Digi International Inc.
  *
  * This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
@@ -1618,7 +1618,7 @@ public void packetReceived(XBeePacket receivedPacket) {
 	private void writePacket(XBeePacket packet) throws IOException {
 		logger.debug(toString() + "Sending XBee packet: \n{}", packet.toPrettyString());
 		// Write bytes with the required escaping mode.
-		switch (operatingMode) {
+		switch (getOperatingMode()) {
 		case API:
 		default:
 			connectionInterface.writeData(packet.generateByteArray());