Pin a specific version of nginx.
Pin a specific version of nginx.

This commit will pretend to break images as soon as a newer ubuntu-nginx release appears.
chambm/docker-galaxy-stable,bgruening/docker-galaxy-stable,afgane/docker-galaxy-stable,afgane/docker-galaxy-stable,chambm/docker-galaxy-stable,bgruening/docker-galaxy-stable,kellrott/docker-galaxy-stable,bgruening/docker-galaxy-stable,kellrott/docker-galaxy-stable,afgane/docker-galaxy-stable,chambm/docker-galaxy-stable,kellrott/docker-galaxy-stable