fix DiffHelper tests on S3
fix DiffHelper tests on S3

washort/zamboni,tsl143/zamboni,ayushagrawal288/zamboni,jasonthomas/zamboni,diox/zamboni,elysium001/zamboni,ayushagrawal288/zamboni,jasonthomas/zamboni,ddurst/zamboni,shahbaz17/zamboni,mozilla/zamboni,mozilla/zamboni,washort/zamboni,ingenioustechie/zamboni,ingenioustechie/zamboni,jasonthomas/zamboni,shahbaz17/zamboni,ddurst/zamboni,diox/zamboni,mozilla/zamboni,tsl143/zamboni,elysium001/zamboni,luckylavish/zamboni,ingenioustechie/zamboni,washort/zamboni,diox/zamboni,ayushagrawal288/zamboni,ddurst/zamboni,diox/zamboni,shahbaz17/zamboni,ingenioustechie/zamboni,jasonthomas/zamboni,elysium001/zamboni,luckylavish/zamboni,shahbaz17/zamboni,ayushagrawal288/zamboni,tsl143/zamboni,tsl143/zamboni,washort/zamboni,luckylavish/zamboni,elysium001/zamboni,mozilla/zamboni,ddurst/zamboni,luckylavish/zamboni