nixpkgs

c78c5e98 - gitlab: 8.17.4 -> 8.17.5

gitlab: 8.17.4 -> 8.17.5 Fixes security issues: https://about.gitlab.com/2017/04/05/gitlab-9-dot-0-dot-4-security-release/ (cherry picked from commit d3ef8dc63353736679c10bbcc879b3a5252fe237)