Undesired lines in screen pipeline/new separating variables field

As commented by @dimitrieh in https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/27473#note_173809577:

"A new hr is introduced between the variables. This should only appear at the bottom of the list similar as how it's done within project settings view."

To see this bug, in a project go to -/pipelines/new