WASM REPL: fix for ACE setup in Chromium

Author: adqm

Tools/wasm/emscripten/web_example/index.html

@@ -594,6 +594,7 @@
                     finishedCallback,
                 );
             };
+        var editor;
         document.addEventListener('DOMContentLoaded', () => {
             editor = ace.edit("editor");
             editor.session.setMode("ace/mode/python");