engine: Improve compatibility with some base images
engine: Improve compatibility with some base images

On some old distributions useradd does not support -N switch,
so don't use it.

Signed-off-by: Dmitry Fleytman <a8cf97adadec4e1b734a39bc5aea71b5741cfca1@daynix.com>

daynix/rebuild,rbld/rebuild,daynix/rebuild,rbld/rebuild,daynix/rebuild,rbld/rebuild