www/gitlab fixed dependency problem to textproc/rubygem-html-pipeline version 2.7.x

[mfechner]

Summary

Commit message:
Fixed dependency problem to textproc/rubygem-html-pipeline version 2.7.x.

Reviewed by: tz/swills (mentor)
Approved by: tz/swills (mentor)
Differential Revision: URL to this revision

Test Plan

All patches are build, you can find all build logs:
https://pkg.fechner.net/jail.html?mastername=111amd64-gitlab

The fresh packages are tested against a new installation using:
https://gitlab.fechner.net/mfechner/Gitlab-vagrant

An old version is updated following the manual:
https://gitlab.fechner.net/mfechner/Gitlab-docu

[tz]

You could also include the "Reported by:" header, if some reports the issue to you. Its not needed for me, just want to point it out.