(Reuters) - EBay Inc added $3 billion (£2 billion) to its 2020 share buyback plan and forecast current-quarter profit above analysts' expectations on Thursday after closing the sale of its StubHub ticketing unit.The company is expanding its buyback plans to $4.5 billion.EBay expects to post first-quarter adjusted profit of between 72 cents and 75 cents, while analysts are expecting 72 cents, according to Refinitiv data.The outlook reflects the benefit of share buybacks and investment timing,..