Preserve token config keys on save

[ghost]

When adding or updating a stream from the UI, server.token.enabled gets removed from the config if false.

The new config.json compared to the provided (default) one after save with this change:

--- config.json
+++ config.json
@@ -7,24 +7,24 @@
     "http_login": "demo",
     "http_password": "demo",
     "http_port": ":8083",
-    "log_level": "debug",
-    "rtsp_port": ":5541",
     "https": false,
-    "https_port": ":443",
+    "https_auto_tls": false,
+    "https_auto_tls_name": "",
     "https_cert": "server.crt",
     "https_key": "server.key",
+    "https_port": ":443",
+    "log_level": "debug",
+    "rtsp_port": ":5541",
     "token": {
-      "enable": false,
-      "backend": "http://127.0.0.1/test.php"
+      "backend": "http://127.0.0.1/test.php",
+      "enable": false
     }
-},
+  },
   "streams": {
     "demo": {
       "channels": {
         "0": {
           "debug": true,
-          "on_demand": false,
-          "insecure_skip_verify": true,
           "url": "rtsp://admin:deep18rwip@176.117.205.3:5541/video1"
         }
       },