s/var/let/

lib/routes/hackmd.js

@@ -34,7 +34,7 @@ module.exports = function(crowi, app) {
       agentScriptContentTpl = swig.compileFile(agentScriptPath);
     }
 
-    var origin = `${req.protocol}://${req.get('host')}`;
+    let origin = `${req.protocol}://${req.get('host')}`;
 
     // use config.crowi['app:url'] when exist req.headers['x-forwarded-proto'].
     // refs: lib/crowi/express-init.js