Go back to gitlab-workhorse 0.7.1

We found out that 0.7.2 breaks shallow `git clone`. GitLab 8.7 will
work fine with gitlab-workhorse 0.7.1 too.

GITLAB_WORKHORSE_VERSION

@@ -1 +1 @@
-0.7.2
+0.7.1

doc/install/installation.md

@@ -352,7 +352,7 @@ 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 v0.7.2
+    sudo -u git -H git checkout v0.7.1
     sudo -u git -H make
 
 ### Initialize Database and Activate Advanced Features

doc/update/8.6-to-8.7.md

@@ -58,7 +58,7 @@ GitLab 8.1.
 ```bash
 cd /home/git/gitlab-workhorse
 sudo -u git -H git fetch --all
-sudo -u git -H git checkout v0.7.2
+sudo -u git -H git checkout v0.7.1
 sudo -u git -H make
 ```