relay_frames: make the methods to delete relay frame callbacks public

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

Author: rubenmoral

digi/xbee/devices.py

@@ -2579,19 +2579,19 @@ def del_expl_data_received_callback(self, callback):
         """
         super()._del_expl_data_received_callback(callback)
 
-    def _del_user_data_relay_received_callback(self, callback):
+    def del_user_data_relay_received_callback(self, callback):
         """
         Override.
         """
         super()._del_user_data_relay_received_callback(callback)
 
-    def _del_bluetooth_data_received_callback(self, callback):
+    def del_bluetooth_data_received_callback(self, callback):
         """
         Override.
         """
         super()._del_bluetooth_data_received_callback(callback)
 
-    def _del_micropython_data_received_callback(self, callback):
+    def del_micropython_data_received_callback(self, callback):
         """
         Override.
         """