Update GitLab Workhorse to v1.0.1

v1.0.0 was mistakenly tagged with a lightweight, rather than annotated, tag,
which caused compiled versions of workhorse to wrongly report their version.

GITLAB_WORKHORSE_VERSION

-1.0.0
+1.0.1

changelogs/unreleased/workhorse-v1-0-1.yml

+---
+title: Update GitLab Workhorse to v1.0.1
+merge_request: 7759
+author: 

doc/install/installation.md

@@ -403,7 +403,7 @@ If you are not using Linux you may have to run `gmake` instead of
     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 v1.0.0
+    sudo -u git -H git checkout v1.0.1
     sudo -u git -H make
 ### Initialize Database and Activate Advanced Features

doc/update/8.13-to-8.14.md

@@ -84,7 +84,7 @@ GitLab 8.1.
 ```bash
 cd /home/git/gitlab-workhorse
 sudo -u git -H git fetch --all
-sudo -u git -H git checkout v1.0.0
+sudo -u git -H git checkout v1.0.1
 sudo -u git -H make
 ```