devices: fix the message displayed when the XBee device protocol is not correct

Signed-off-by: Diego Escalona <diego.escalona@digi.com>

Author: diescalo

digi/xbee/devices.py

@@ -316,7 +316,7 @@ def read_device_info(self):
 
         if orig_protocol is not None and orig_protocol != XBeeProtocol.UNKNOWN and orig_protocol != self._protocol:
             raise XBeeException("Error reading device information: "
-                                "Your module seems to be %s and NOT %s. " % (self.get_protocol(), orig_protocol) +
+                                "Your module seems to be %s and NOT %s. " % (self._protocol, orig_protocol) +
                                 "Check if you are using the appropriate device class.")
 
         # 64-bit address: