EAST LONDON, South Africa — By the middle of December, the Areena Riverside Resort market was practically empty. The once-packed area — where tourists used to come from the city center of the Eastern Cape province to buy vegetables, clothing, art, books and beauty supplies — had shrunk from more than 20 stalls down to nine. Rene Rens, a vendor who sells plants to supplement her income, said that after the country’s “festive season” concluded, she planned to close up shop, too.