[FIX] *: enforce 1 newline on files end

Part-of: odoo/documentation#2983

content/administration/maintain/hosting_changes.rst

@@ -85,4 +85,3 @@ From Odoo.sh to on-premises
 
 1.  Grab a :ref:`backup of your Odoo.sh production database <odoo_sh_branches_backups>`.
 2.  Restore it from the database manager on your local server.
-

content/administration/odoo_sh/advanced/frequent_technical_questions.rst

@@ -29,4 +29,3 @@ We advise that:
 - Your scheduled actions should be
   `idempotent <https://stackoverflow.com/a/1077421/3332416>`_: they must not
   cause side-effects if they are started more often than expected.
-

content/administration/upgrade.rst

@@ -254,4 +254,4 @@ Agreement <upgrade>` page.
 .. seealso::
    - :doc:`upgrade/faq`
    - :doc:`odoo_sh`
-   - :doc:`maintain/supported_versions`
+   - :doc:`maintain/supported_versions`

content/administration/upgrade/on_premise.rst

@@ -56,4 +56,4 @@ Depending on your contract, the upgrade of your custom modules can be done
 
 #. by yourself.
 #. by your Partner.
-#. by Odoo (if you hold a subscription to 'Maintenance of Customizations').
+#. by Odoo (if you hold a subscription to 'Maintenance of Customizations').