docker: update all i386 image sources

Use images from a non-official but officialy annouced on the main-stream
docker repository, than using our personal and not-so-maintained images.

https://github.com/docker-library/official-images#architectures-other-than-amd64

Change-Id: I7781aead8e2cfdda19d086842f35f2d9739f3533
Note: add also 17.10_i386 dockerfile