Merge branch 'gitlab-workhorse-0.5.1' into 'master'

Use gitlab-workhorse 0.5.1

Improves relative URL support.

See merge request !2134

GITLAB_WORKHORSE_VERSION

-0.5.0
+0.5.1

doc/install/installation.md

@@ -348,7 +348,7 @@ GitLab Shell is an SSH access and repository management software developed speci
     cd /home/git
     sudo -u git -H git clone https://gitlab.com/gitlab-org/gitlab-workhorse.git
     cd gitlab-workhorse
-    sudo -u git -H git checkout 0.5.0
+    sudo -u git -H git checkout 0.5.1
     sudo -u git -H make
 
 ### Initialize Database and Activate Advanced Features

doc/update/8.2-to-8.3.md

@@ -78,7 +78,7 @@ which should already be on your system from GitLab 8.1.
 ```bash
 cd /home/git/gitlab-workhorse
 sudo -u git -H git fetch --all
-sudo -u git -H git checkout 0.5.0
+sudo -u git -H git checkout 0.5.1
 sudo -u git -H make
 ```