Leap Wireless International, Inc. (NASDAQ:LEAP) has been sued by one of its shareholders who believes that AT&T Inc. (NYSE:T)’s $1.2 billion buyout offer significantly undervalues the company’s actual worth. The Booth Family Trust alleges that Leap directors acted in bad faith when they set the price at $15 per share, Bloomberg’s Phil Milford reports. Leap Wireless International, Inc. (NASDAQ:LEAP), which sells pay-as-you-go mobile services through its subsidiary Cricket, announced that it would join AT&T on July 12, but Booth lawyers contend that the transaction “fails to maximize shareholder value” because it does not account for the company’s growth potential or…