env/linux-x86-std-kube: use correct tags for Docker images
env/linux-x86-std-kube: use correct tags for Docker images

Updates golang/go#12546

Change-Id: Icaa0504791522837fcbf0256b144c13158777c6e
Reviewed-on: https://go-review.googlesource.com/15258
Reviewed-by: Andrew Gerrand <395a7d33bec8475c9b83b7d440f141bcbd994aa5@golang.org>

proppy/build,proppy/build,golang/build,proppy/build,golang/build,proppy/build,golang/build,golang/build