PARIS—For the second year in a row, the traditional French Open schedule is being disrupted by the coronavirus pandemic. The clay-court Grand Slam tennis tournament said Thursday it will push back the start of this season’s event by one week because of surging virus cases in France. “This postponement will give us a little more time to improve the health situation and should allow us to optimize our chances of welcoming spectators at Roland Garros,” said Gilles Moretton, the president of the French tennis federation. “Whether for the fans, the players or the atmosphere, crowd presence is essential to the tournament, the first international sporting event of the spring.” The French Open was scheduled to start on May 23, but first-round matches will now get underway on May 30. Last year’s tournament was pushed back to September because of the pandemic, with crowds limited to 1,000 per day. The delay …