Emscripten: fix typo in emscripten-shell.html

Author: Aida Torajiro

resources/emscripten/emscripten-shell.html

@@ -270,7 +270,7 @@
 
 /** @type {{[key: number]: Gamepad}} */
 let gamepads = {};
-const haveEvents = 'ongamepadonnected' in window;
+const haveEvents = 'ongamepadconnected' in window;
 
 function addGamepad(gamepad) {
   if (gamepad == undefined) {