SAN DIEGO — Former San Diego Mayor Maureen O’Connor took $2 million from a nonprofit foundation to feed a gambling addiction in which she lost more than $1 billion over an eight-year period, federal prosecutors said Thursday. O’Connor, 66, appeared in federal court and pleaded not guilty to a money laundering charge as part of a deferred prosecution. Under the arrangement with federal prosecutors, she has two years to repay the $2 million taken from the R.P. Foundation, a nonprofit set up by her late husband, Robert O. Peterson. Peterson was the co-founder of the Jack-In-The-Box restaurant chain and later...