Add missing HMD_ALLOW_ORIGIN variable

Author: bananaappletw

app.json

@@ -35,11 +35,16 @@
             "description": "sub url path, like `www.example.com/<URL_PATH>`",
             "required": false
         },
-        "HMD_ALLOW_ORIGIN": {
+        "HMD_PORT": {
             "description": "web app port",
             "required": false,
             "value": "80"
         },
+        "HMD_ALLOW_ORIGIN": {
+            "description": "domain name whitelist (use comma to separate)",
+            "required": false,
+            "value": "localhost"
+        },
         "HMD_PROTOCOL_USESSL": {
             "description": "set to use ssl protocol for resources path (only applied when domain is set)",
             "required": false