Update installation.md

doc/install/installation.md

@@ -303,7 +303,7 @@ sudo usermod -aG redis git
     # Clone GitLab repository
     sudo -u git -H git clone https://gitlab.com/gitlab-org/gitlab-ce.git -b 11-0-stable gitlab
 
-**Note:** You can change `11-1-stable` to `master` if you want the *bleeding edge* version, but never install master on a production server!
+**Note:** You can change `11-0-stable` to `master` if you want the *bleeding edge* version, but never install master on a production server!
 
 ### Configure It