code: add some code that does not have "use strict" being set

Signed-off-by: Yonle <yonle@lecturify.net>

config.js.example

@@ -1,3 +1,4 @@
+"use strict";
 
 // Bostr config
 

package.json

@@ -1,6 +1,6 @@
 {
   "name": "bostr",
-  "version": "3.0.1",
+  "version": "3.0.2",
   "description": "Nostr relay bouncer",
   "main": "index.js",
   "scripts": {

testworker.js

@@ -1,3 +1,4 @@
+"use strict";
 const { Worker } = require("worker_threads");
 const worker = new Worker(__dirname + "/worker_bouncer.js", { name: "Bostr (worker)" });