add changelog entry about running worker command without invoking shell
add changelog entry about running worker command without invoking shell

mihailim/image_optim,toy/image_optim,ramiroaraujo/image_optim,weheartit/image_optim,toy/image_optim,ramiroaraujo/image_optim,weheartit/image_optim,toy/image_optim,weheartit/image_optim,ramiroaraujo/image_optim,mihailim/image_optim,mihailim/image_optim