Update comment about legacy pipeline triggers
What does this MR do?
Addresses outdated comment. See https://gitlab.com/gitlab-org/gitlab-ce/commit/4407d3cf19bc815142ea3a7908003e85efde76ed#note_139125721 for details.
Addresses outdated comment. See https://gitlab.com/gitlab-org/gitlab-ce/commit/4407d3cf19bc815142ea3a7908003e85efde76ed#note_139125721 for details.