Instead of hardcoding laforge's username in all FROM statements in the
Dockerfiles, make use of the USER variable (as passed through by the
"make/Makefile" with "docker build --build-arg USER=..."). Thanks to
fixeria for proposing this fix!
This requires running docker-ce, old versions of docker (such as the
one in the official repositories of the latest Fedora) don't support
variables in the FROM line. But docker-ce can be installed after
adding docker's 3rd party repositories.
Closes: OS#3457
Change-Id: Ic5f11c8a4e247f632cb6aea6d147e94c53e0130f
Harald Welte
Oliver Smith