typo fixed

fixed a typo in an url to gitlab-ssl. Now it does not return the 404 error

doc/update/6.x-or-7.x-to-7.8.md

@@ -179,7 +179,7 @@ sudo cp lib/support/logrotate/gitlab /etc/logrotate.d/gitlab
 ### Change Nginx settings
 
 * HTTP setups: Make `/etc/nginx/sites-available/gitlab` the same as https://gitlab.com/gitlab-org/gitlab-ce/blob/7-8-stable/lib/support/nginx/gitlab but with your settings.
-* HTTPS setups: Make `/etc/nginx/sites-available/gitlab-ssl` the same as https://gitlab.com/gitlab-org/gitlab-ce/blob/7-8-stablef/lib/support/nginx/gitlab-ssl but with your settings.
+* HTTPS setups: Make `/etc/nginx/sites-available/gitlab-ssl` the same as https://gitlab.com/gitlab-org/gitlab-ce/blob/7-8-stable/lib/support/nginx/gitlab-ssl but with your settings.
 * A new `location /uploads/` section has been added that needs to have the same content as the existing `location @gitlab` section.
 
 ## 9. Start application