Makes reCAPTCHA configurable through Application Settings screen
Following the work made by @stanhu here: https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/2216, made it configurable without needing to restart Gitlab
Following the work made by @stanhu here: https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/2216, made it configurable without needing to restart Gitlab