South African billionaire and one of the two richest men in Africa, Johann Rupert has fallen below Nigeria’s Aliko Dangote, making Dangote Africa’s richest man. Both billionaires have been in rat race for the elusive title, and none of them for a few months now have taken a commanding lead. Johann Rupert has been surpassed by Aliko Dangote as Africa’s richest man.The title of Africa’s richest man changed hands three times in August.Dangote currently has a net worth of $13.2 billion, slightly higher than Johann Rupert’s $13.1 billion.Johann Rupert and Aliko Dangote, two of Africa’s wealthiest i…