Adapt GitLab to 5.1 final.

Update gitlab submodule.

M  .cpl/_deps:
  Add app 'nodejs'
A  .cpl/params/nodejs:
  Compile app 'nodejs'
M  .gitignore:
  Ignore '/gitlab/puma.rb', generated by template.
M  gitlab/github:
  Update commit 5.1 (75fbdc40eb6c46a5a1a5d95a314dad0b3eeda299)
M  gitlab/install_or_update_gitlab.sh.tpl:
  Fixes test for gitlab-shell install.
  Update global config for ruby modules