let nginx return a 503 when in maintenance mode
let nginx return a 503 when in maintenance mode

gitlabhq/gitlab-contributors,amitsuroliya/rails-contributors,gitlabhq/gitlab-contributors,fxn/rails-contributors,maclover7/rails-contributors,amitsuroliya/rails-contributors,fxn/rails-contributors,maclover7/rails-contributors,maclover7/rails-contributors,maclover7/rails-contributors,amitsuroliya/rails-contributors,fxn/rails-contributors,amitsuroliya/rails-contributors,fxn/rails-contributors,gitlabhq/gitlab-contributors,gitlabhq/gitlab-contributors