Fix link to gitlab.yml.example in paragraph 5

doc/update/7.6-to-7.7.md

@@ -67,7 +67,7 @@ sudo cp lib/support/init.d/gitlab /etc/init.d/gitlab
 
 #### New configuration options for `gitlab.yml`
 
-There are new configuration options available for [`gitlab.yml`](config/gitlab.yml.example). View them with the command below and apply them to your current `gitlab.yml`.
+There are new configuration options available for [`gitlab.yml`](/config/gitlab.yml.example). View them with the command below and apply them to your current `gitlab.yml`.
 
 ```
 git diff origin/7-6-stable:config/gitlab.yml.example origin/7-7-stable:config/gitlab.yml.example