util: Fix stream write issue in Async::upload_file()
util: Fix stream write issue in Async::upload_file()

ingve/IncludeOS,AnnikaH/IncludeOS,alfred-bratterud/IncludeOS,mnordsletten/IncludeOS,AndreasAakesson/IncludeOS,AndreasAakesson/IncludeOS,alfred-bratterud/IncludeOS,hioa-cs/IncludeOS,alfred-bratterud/IncludeOS,AndreasAakesson/IncludeOS,alfred-bratterud/IncludeOS,alfred-bratterud/IncludeOS,hioa-cs/IncludeOS,ingve/IncludeOS,AnnikaH/IncludeOS,mnordsletten/IncludeOS,AndreasAakesson/IncludeOS,hioa-cs/IncludeOS,hioa-cs/IncludeOS,hioa-cs/IncludeOS,mnordsletten/IncludeOS,ingve/IncludeOS,mnordsletten/IncludeOS,AnnikaH/IncludeOS,AndreasAakesson/IncludeOS,mnordsletten/IncludeOS,AnnikaH/IncludeOS,mnordsletten/IncludeOS,ingve/IncludeOS,AndreasAakesson/IncludeOS,ingve/IncludeOS,AnnikaH/IncludeOS