UnityEventCompactDrawer throwing null reference exception for lists with 0 events

[soraphis]

element in this line:
https://github.com/neon-age/Smart-Inspector/blob/main/Drawers/UnityEventCompactDrawer.cs#L272

is null, when m_ListenersArray.arraySize == 0

adding

        if (m_ListenersArray.arraySize == 0)
            return 0;

solves the issue for me