add a 404 to games if it doesnt exist :3

src/libpoketube/init/pages-static.js

@@ -211,10 +211,19 @@ module.exports = function (app, config, renderTemplate) {
   });
 
 app.get("/game-hub", function (req, res) {
+  var gameslist = ["pong", "tic-tac-toe", "sudoku", "snake"];
+  var requestedGame = req.query.game;
+
+  if (!requestedGame || !gameslist.includes(requestedGame)) {
+    return renderTemplate(res, req, "404.ejs");
+  }
+
   renderTemplate(res, req, "gamehub.ejs", {
-      game: req.query.game,
+    game: requestedGame,
   });
 });
+
+
   app.get("/static/:id", (req, res) => {
     const id = req.params.id;