Update gitlab to version 10.7.5 and fix some small other issues

[mfechner]

Summary

Question: can I commit this as one commit or should I commit it separately?

Combined changes are and will also be part of the commit message:
Applied security upgrade to gitlab 10.7.5.
Fixed bug with wrong path for gitlab-workhouse that should fix artifacts (reported by Felix <[e-mail]>). This was fix upstream but is not included in this version yet: https://gitlab.com/gitlab-org/gitlab-ce/issues/46763
Update net/rubygem-grpc to 1.11.1 which is required for gitlab 10.7.5.
Sync dep net/rubygem-grpc with gitlab which uses now 1.11.1.
Added gitlab-pages again to dependencies as the new version builds again.

Test Plan

All patches are build using poudriere, everything was tested in a VM to run correctly.

[swills]

LGTM. I'd say doing it as one commit is fine.

Thanks in particular for fixing the tmp/upload vs uploads thing, I ran into that issue.