PayPal Holdings Inc. reported slowing growth in its card-processing business even as fourth-quarter earnings topped analysts’ estimates.Growth in the total payment volume for PayPal’s unbranded payment-processing business — the volume of payments it processes for other firms, not itself — slipped to 2% in the fourth quarter from from 29% a year earlier, a deceleration the firm attributed to an intentional effort to price its technology more competitively. Branded checkout growth also fell short ...