TOKYO (Reuters) - Oil prices edged lower in quiet trade on Tuesday as concerns about slower economic growth overshadowed signs of a thawing in the trade war between Washington and Beijing, while investors awaited U.S. inventory data.Brent futures were down 3 cents at $61.54 a barrel by 0137 GMT, having fallen 0.7% on Monday. U.S. West Texas Intermediate (WTI) crude was down 9 cents at $55.72, after falling 1.5% in the previous session.Prices rose sharply last week amid a decline in U.S...