gitlab: Upgrade gitlab-shell & gitlab-workhorse to versions which propagate $HOME

As was described in the previous patch, we need $HOME to be propagated
by this programs so that git can find partition's .gitconfig.

Specifically we need the following patches to be present in our build:

    https://gitlab.com/gitlab-org/gitlab-shell/commit/9e087f64
    https://gitlab.com/gitlab-org/gitlab-workhorse/commit/b5f1b803

They both have been applied upstream very close to revisions we
previously had in software.cfg, so we only need to update the revisions
to get them.

/cc @kazuhiko, @jerome

software/gitlab/software.cfg

@@ -101,14 +101,15 @@ location = ${buildout:parts-directory}/gitlab
 <= git-repository
 repository = https://gitlab.com/gitlab-org/gitlab-shell.git
 # gitlab 8.2 wants gitlab-shell 2.6.8
-revision = v2.6.8-0-g1a75d086b53d799ac10f77acfb198f2c5ea95621
+# 2.6.8 + NXD patches
+revision = v2.6.8-2-g216d7e15fe06917198891a895f762ba84fdcc4d4
 location = ${buildout:parts-directory}/gitlab-shell
 
 [gitlab-workhorse-repository]
 <= git-repository
 repository = https://gitlab.com/gitlab-org/gitlab-workhorse.git
-# 0.4.X
-revision = 0.4.1-3-g9123131eab0de3b896b8c365dc8f8892c13f70a9
+# 0.4.X + NXD patches
+revision = 0.4.1-10-g0d0bd209eea7441a3b4202c2e00a989cf340ee86
 location = ${buildout:parts-directory}/gitlab-workhorse