Netflix Inc. credited the pandemic with delivering record growth in 2020. Now it’s blaming the pandemic for the worst first quarter in eight years. The streaming service added far fewer new customers than Wall Street expected in the first three months of 2021, even missing its own forecast by millions of subscribers. And the current quarter will be more challenging, Netflix said Tuesday, predicting a gain of just 1 million new customers -- or a fraction of the 4.44 million projected by analysts. Netflix has been warning for months that growth would slow after customers emerged from their Covid-19 hibernation, but few expected the company to stall so dramatically. The first quarter of 2020 was the strongest in its history, reeling in 15.8 million new customers, and Netflix’s pace was still brisk in the fourth quarter.