prevent possible crash when trying to start esc32 logging with nothing connected.
prevent possible crash when trying to start esc32 logging with nothing connected.

AutoQuad/qgroundcontrol_aq,hejunbok/qgroundcontrol_aq,AutoQuad/qgroundcontrol_aq,AutoQuad/qgroundcontrol_aq,hejunbok/qgroundcontrol_aq,hejunbok/qgroundcontrol_aq,AutoQuad/qgroundcontrol_aq,hejunbok/qgroundcontrol_aq