remove harden-ssh as it got deprecated

Signed-off-by: Simon L. <szaimen@e.mail.de>

docs/restore-backup.md

@@ -89,7 +89,6 @@ If the Nextcloud web interface works as expected, you will need to reinstall all
 ### Optional are those
 (You only need to reinstall them **if they were installed before**)
 - Reenable the Firewall on your server ([instructions](./firewall))
-- Reharden the SSH configuration ([instructions](./harden-ssh))
 - Reinstall OnlyOffice for Nextcloud ([instructions](./onlyoffice))
 - Reinstall High-Performance backend for Nextcloud Talk ([instructions](./hpb))
 - Reinstall Push Notifications for Nextcloud ([instructions](./notify_push))

news/2021-03-11-firewall-and-harden-ssh.md

@@ -1,5 +1,5 @@
 ---
-title: Enable Firewall and Harden SSH
+title: Enable Firewall
 author: szaimen
 author_title: Creator of Nextcloud-NAS-Guide
 author_url: https://github.com/szaimen
@@ -14,8 +14,6 @@ There are two new options available that make your server even more secure.
 
 You can find the instructions how and why you should enable the Firewall on your server here: [click here](/docs/firewall)
 
-The instructions how and why you should harden your SSH configuration are here: [click here](/docs/harden-ssh)
-
 ![Secure server](/news/undraw_secure_server_s9u8.svg)
 
 <!--The following comment will skip the article in the News overview.-->

sidebars.js

@@ -12,7 +12,7 @@ module.exports = {
     "SMB-server and user accounts": ['smb-server', 'run-smb-server', 'create-users', 'create-shares', 'recycle-bin-cleanup'],
     "Customize Nextcloud": ['customize-nextcloud', 'previewgenerator', 'cookielifetime', 'share-folder', 'workspaces', 'user-flows'],
     "Activate Let's Encrypt": ['activate-lets-encrypt', 'ddns', 'ddns-providers', 'activate-ddns', 'configure-ddclient', 'port-forwarding', 'activate-tls', 'congratulations'],
-    "Optional": [ {"Server Addons": ['firewall', 'harden-ssh', 'vaultwarden', 'pi-hole', 'pivpn', 'pms', 'remotedesktop']}, 
+    "Optional": [ {"Server Addons": ['firewall', 'vaultwarden', 'pi-hole', 'pivpn', 'pms', 'remotedesktop']}, 
           {"Nextcloud Addons": ['share-link-audit', 'onlyoffice', 'hpb', 'notify_push', 'pdfannotate', 'whiteboard', 'pico', 'extract', 'more-apps']}, 
           {"Miscellaneous": ['digitize', 'change-update-time', 'home-access-only']}
       ],