fix formatting issue

fix formatting issue with self-signed certificate section

doc/install/installation.md

@@ -356,7 +356,8 @@ To use GitLab with HTTPS:
     1. Review the configuration file and consider applying other security and performance enhancing features.
 
 Using a self-signed certificate is discouraged but if you must use it follow the normal directions then:
-    1. Generate a self-signed SSL certificate:
+
+1. Generate a self-signed SSL certificate:
 
     ```
     mkdir -p /etc/nginx/ssl/
@@ -364,8 +365,7 @@ Using a self-signed certificate is discouraged but if you must use it follow the
     sudo openssl req -newkey rsa:2048 -x509 -nodes -days 3560 -out gitlab.crt -keyout gitlab.key
     sudo chmod o-r gitlab.key
     ```
-
-    1. In the `config.yml` of gitlab-shell set `self_signed_cert` to `true`.
+1. In the `config.yml` of gitlab-shell set `self_signed_cert` to `true`.
 
 ### Additional Markup Styles