fix icon/screenshot previews in Nightly (bug 812162)
fix icon/screenshot previews in Nightly (bug 812162)

Prashant-Surya/addons-server,lavish205/olympia,crdoconnor/olympia,Jobava/zamboni,mrrrgn/olympia,eviljeff/olympia,ingenioustechie/zamboni,mozilla/olympia,andymckay/olympia,wagnerand/zamboni,mozilla/zamboni,Jobava/zamboni,Joergen/olympia,Witia1/olympia,johancz/olympia,yfdyh000/olympia,mrrrgn/olympia,eviljeff/olympia,tsl143/zamboni,mozilla/zamboni,washort/zamboni,kumar303/addons-server,ayushagrawal288/zamboni,Prashant-Surya/addons-server,clouserw/zamboni,mstriemer/zamboni,tsl143/addons-server,eviljeff/olympia,eviljeff/zamboni,anaran/olympia,yfdyh000/olympia,anaran/olympia,muffinresearch/addons-server,spasovski/zamboni,SuriyaaKudoIsc/olympia,Revanth47/addons-server,kumar303/addons-server,beni55/olympia,ayushagrawal288/zamboni,atiqueahmedziad/addons-server,Hitechverma/zamboni,wagnerand/zamboni,ddurst/zamboni,mrrrgn/olympia,ingenioustechie/zamboni,mudithkr/zamboni,muffinresearch/olympia,andymckay/olympia,mozilla/addons-server,wagnerand/zamboni,wagnerand/addons-server,andymckay/addons-server,mstriemer/zamboni,tsl143/addons-server,ngokevin/zamboni,bqbn/addons-server,luckylavish/zamboni,koehlermichael/olympia,luckylavish/zamboni,mudithkr/zamboni,magopian/olympia,Joergen/olympia,mdaif/olympia,mozilla/olympia,jamesthechamp/zamboni,atiqueahmedziad/addons-server,Joergen/zamboni,mozilla/zamboni,ddurst/zamboni,anaran/olympia,Witia1/olympia,Joergen/olympia,shahbaz17/zamboni,aviarypl/mozilla-l10n-addons-server,spasovski/zamboni,magopian/olympia,kmaglione/olympia,shahbaz17/zamboni,koehlermichael/olympia,Nolski/olympia,wagnerand/addons-server,andymckay/olympia,tsl143/zamboni,robhudson/zamboni,andymckay/olympia,mozilla/zamboni,jasonthomas/zamboni,shahbaz17/zamboni,Joergen/olympia,kumar303/zamboni,tsl143/zamboni,eviljeff/zamboni,psiinon/addons-server,Nolski/olympia,ingenioustechie/zamboni,andymckay/zamboni,harikishen/addons-server,wagnerand/zamboni,mozilla/addons-server,muffinresearch/olympia,elysium001/zamboni,elysium001/zamboni,Hitechverma/zamboni,crdoconnor/olympia,jasonthomas/zamboni,SuriyaaKudoIsc/olympia,Jobava/zamboni,kumar303/addons-server,harry-7/addons-server,mstriemer/olympia,kumar303/olympia,kmaglione/olympia,ingenioustechie/zamboni,lavish205/olympia,mstriemer/olympia,magopian/olympia,diox/zamboni,SuriyaaKudoIsc/olympia,robhudson/zamboni,harry-7/addons-server,Witia1/olympia,tsl143/zamboni,washort/zamboni,Joergen/zamboni,mdaif/olympia,muffinresearch/addons-server,Revanth47/addons-server,Nolski/olympia,johancz/olympia,Hitechverma/zamboni,luckylavish/zamboni,Prashant-Surya/addons-server,beni55/olympia,elysium001/zamboni,mstriemer/zamboni,jpetto/olympia,jamesthechamp/zamboni,tsl143/addons-server,beni55/olympia,johancz/olympia,SuriyaaKudoIsc/olympia,harry-7/addons-server,diox/zamboni,atiqueahmedziad/addons-server,magopian/olympia,psiinon/addons-server,aviarypl/mozilla-l10n-addons-server,beni55/olympia,jasonthomas/zamboni,kmaglione/olympia,harikishen/addons-server,andymckay/addons-server,atiqueahmedziad/addons-server,kumar303/zamboni,anaran/olympia,ddurst/zamboni,harikishen/addons-server,spasovski/zamboni,kumar303/olympia,wagnerand/addons-server,ayushagrawal288/zamboni,koehlermichael/olympia,kumar303/addons-server,kmaglione/olympia,Hitechverma/zamboni,mstriemer/olympia,koehlermichael/olympia,crdoconnor/olympia,andymckay/zamboni,wagnerand/olympia,muffinresearch/olympia,kumar303/olympia,crdoconnor/olympia,shahbaz17/zamboni,washort/zamboni,diox/olympia,andymckay/addons-server,kumar303/zamboni,aviarypl/mozilla-l10n-addons-server,mozilla/addons-server,eviljeff/zamboni,mstriemer/addons-server,jamesthechamp/zamboni,jpetto/olympia,mozilla/addons-server,muffinresearch/addons-server,clouserw/zamboni,muffinresearch/addons-server,mstriemer/zamboni,mudithkr/zamboni,lavish205/olympia,jpetto/olympia,ngokevin/zamboni,spasovski/zamboni,mozilla/olympia,luckylavish/zamboni,mdaif/olympia,koehlermichael/olympia,mstriemer/addons-server,Revanth47/addons-server,ayushagrawal288/zamboni,Nolski/olympia,mdaif/olympia,mstriemer/addons-server,diox/olympia,jpetto/olympia,eviljeff/zamboni,Jobava/zamboni,wagnerand/addons-server,yfdyh000/olympia,jamesthechamp/zamboni,yfdyh000/olympia,Joergen/zamboni,wagnerand/olympia,beni55/olympia,harikishen/addons-server,muffinresearch/olympia,Joergen/zamboni,ddurst/zamboni,wagnerand/olympia,kmaglione/olympia,washort/zamboni,Nolski/olympia,psiinon/addons-server,lavish205/olympia,johancz/olympia,elysium001/zamboni,psiinon/addons-server,mudithkr/zamboni,diox/olympia,mrrrgn/olympia,johancz/olympia,Revanth47/addons-server,yfdyh000/olympia,mstriemer/addons-server,mdaif/olympia,aviarypl/mozilla-l10n-addons-server,ngokevin/zamboni,diox/zamboni,Joergen/zamboni,crdoconnor/olympia,magopian/olympia,bqbn/addons-server,diox/zamboni,muffinresearch/addons-server,harry-7/addons-server,Witia1/olympia,muffinresearch/olympia,jasonthomas/zamboni,clouserw/zamboni,Witia1/olympia,Joergen/zamboni,diox/olympia,clouserw/zamboni,Joergen/olympia,kumar303/zamboni,andymckay/addons-server,robhudson/zamboni,mstriemer/olympia,mozilla/olympia,mrrrgn/oly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