By Karin Strohecker and Libby George LONDON (Reuters) - Angola will decide by November whether to roll over its $1 billion total return swap deal with JPMorgan, or potentially raise the money on international capital markets, a senior debt official told Reuters. JPMorgan and Angola agreed in December a$1 billion, one-year derivative contract known as a total return swap, backed by $1.9 billion in government dollar bonds, which will expire at the end of this year. "We have some options," Dorivaldo Tei ...