Fix pylint

Signed-off-by: Simone Orru <simone.orru@secomind.com>

astarte/device/device_mqtt.py

@@ -179,6 +179,11 @@ def add_interface_from_json(self, interface_json: dict):
         ----------
         interface_json : dict
             See parent class.
+
+        Raises
+        ------
+        DeviceConnectingError
+            When attempting to add an interface while the device if performing a connection.
         """
         if self.__is_connecting:
             raise DeviceConnectingError("Interfaces cannot be added while device is connecting.")
@@ -195,6 +200,13 @@ def remove_interface(self, interface_name: str) -> None:
         ----------
         interface_name : str
             See parent class.
+
+        Raises
+        ------
+        DeviceConnectingError
+            When attempting to add an interface while the device if performing a connection.
+        InterfaceNotFoundError
+            When the provided interface can't be found in the device introspection.
         """
         if self.__is_connecting:
             raise DeviceConnectingError("Interfaces cannot be removed while device is connecting.")