mandos-ctl: Fix --secret when using the dbus-python module
* mandos-ctl (dbus_python_adapter.SystemBus.set_client_property): New; force ByteArray type to be sent for the client property "Secret". (Test_dbus_python_adapter_SystemBus.MockDBusPython_func .mock_dbus_python.SystemBus.get_object.DBusObject.Set): New. (Test_dbus_python_adapter_SystemBus.MockDBusPython_func .mock_dbus_python.SystemBus.get_object.set_property): - '' - (Test_dbus_python_adapter.SystemBus.MockDBusPython_func .mock_dbus_python.ByteArray): - '' - (Test_dbus_python_adapter_SystemBus .test_Set_Secret_sends_bytearray): - '' -