Fix crash when req.query handling

https://expressjs.com/en/5x/api.html#req.query

"As req.query’s shape is based on user-controlled input, all properties and values in this object
are untrusted and should be validated before trusting"

In essence, req.query.xx can be an array OR an array of strings.

src/server.js

@@ -31,8 +31,8 @@ function notFoundHandler(req, res, next) {
 
 async function initializeExpressSync() {
     const app = express();
-    // disable slowloris prevention: https://github.com/nodejs/node/issues/47421
-    const httpServer = http.createServer({ headersTimeout: 0, requestTimeout: 0 }, app); // see also nginx client_header_timeout (30s)
+    // disable slowloris prevention: https://github.com/nodejs/node/issues/47421 . duplicate headers are discarded for the standard headers (https://nodejs.org/api/http.html#messageheaders)
+    const httpServer = http.createServer({ headersTimeout: 0, requestTimeout: 0, joinDuplicateHeaders: false }, app); // see also nginx client_header_timeout (30s)
 
     const wsServer = new ws.Server({ noServer: true }); // in noServer mode, we have to handle 'upgrade' and call handleUpgrade
 
@@ -45,6 +45,7 @@ async function initializeExpressSync() {
 
     app.set('json spaces', 2); // pretty json
     app.enable('trust proxy'); // trust the X-Forwarded-* headers
+    app.set('query parser', 'simple'); // uses the built-in querystring module for query parsing. req.query always has strings or array of strings
 
     const router = new express.Router();
     router.del = router.delete; // amend router.del for readability further on