MAPG-203 fix wrong variable name

public/static/js/game.js

@@ -520,7 +520,7 @@
             scoreInfo.children[1].style.display = 'block';
             document.getElementById('showSummaryButton').style.display = null;
 
-            if (!room || Game.multi.owner) {
+            if (!roomId || Game.multi.owner) {
                 document.getElementById('startNewGameButton').style.display = 'block';
             }