sftpd: deprecate keys and add a new host_keys config param

host_key defines the private host keys as plain list of strings.

Remove the other deprecated config params from the default config too.

Signed-off-by: Nicola Murino <nicola.murino@gmail.com>

sftpgo.json

@@ -12,7 +12,7 @@
       "command": "",
       "http_notification_url": ""
     },
-    "keys": [],
+    "host_keys": [],
     "kex_algorithms": [],
     "ciphers": [],
     "macs": [],
@@ -26,7 +26,6 @@
       "pwd",
       "scp"
     ],
-    "keyboard_interactive_auth_program": "",
     "keyboard_interactive_auth_hook": "",
     "proxy_protocol": 0,
     "proxy_allowed": []
@@ -50,12 +49,10 @@
       "command": "",
       "http_notification_url": ""
     },
-    "external_auth_program": "",
     "external_auth_hook": "",
     "external_auth_scope": 0,
     "credentials_path": "credentials",
-    "pre_login_hook": "",
-    "pre_login_program": ""
+    "pre_login_hook": ""
   },
   "httpd": {
     "bind_port": 8080,