fix(build) don't pollute global state in ESM build

JitsiMeetJS.js

     return attributes;
 }
 
-/**
- * Tries to deal with the following problem: {@code JitsiMeetJS} is not only
- * this module, it's also a global (i.e. attached to {@code window}) namespace
- * for all globals of the projects in the Jitsi Meet family. If lib-jitsi-meet
- * is loaded through an HTML {@code script} tag, {@code JitsiMeetJS} will
- * automatically be attached to {@code window} by webpack. Unfortunately,
- * webpack's source code does not check whether the global variable has already
- * been assigned and overwrites it. Which is OK for the module
- * {@code JitsiMeetJS} but is not OK for the namespace {@code JitsiMeetJS}
- * because it may already contain the values of other projects in the Jitsi Meet
- * family. The solution offered here works around webpack by merging all
- * existing values of the namespace {@code JitsiMeetJS} into the module
- * {@code JitsiMeetJS}.
- *
- * @param {Object} module - The module {@code JitsiMeetJS} (which will be
- * exported and may be attached to {@code window} by webpack later on).
- * @private
- * @returns {Object} - A {@code JitsiMeetJS} module which contains all existing
- * value of the namespace {@code JitsiMeetJS} (if any).
- */
-function _mergeNamespaceAndModule(module) {
-    return (
-        typeof window.JitsiMeetJS === 'object'
-            ? Object.assign({}, window.JitsiMeetJS, module)
-            : module);
-}
-
 /**
  * The public API of the Jitsi Meet library (a.k.a. {@code JitsiMeetJS}).
  */
-export default _mergeNamespaceAndModule({
+export default {
 
     version: '{#COMMIT_HASH#}',
 
         ScriptUtil,
         browser
     }
-});
+};

index.js

-// For legacy purposes, preserve the UMD of the public API of the Jitsi Meet
-// library (a.k.a. JitsiMeetJS).
-module.exports = require('./JitsiMeetJS').default;
+const ljm = require('./JitsiMeetJS').default;
+
+/**
+ * Tries to deal with the following problem: {@code JitsiMeetJS} is not only
+ * this module, it's also a global (i.e. attached to {@code window}) namespace
+ * for all globals of the projects in the Jitsi Meet family. If lib-jitsi-meet
+ * is loaded through an HTML {@code script} tag, {@code JitsiMeetJS} will
+ * automatically be attached to {@code window} by webpack. Unfortunately,
+ * webpack's source code does not check whether the global variable has already
+ * been assigned and overwrites it. Which is OK for the module
+ * {@code JitsiMeetJS} but is not OK for the namespace {@code JitsiMeetJS}
+ * because it may already contain the values of other projects in the Jitsi Meet
+ * family. The solution offered here works around webpack by merging all
+ * existing values of the namespace {@code JitsiMeetJS} into the module
+ * {@code JitsiMeetJS}.
+ *
+ * @param {Object} module - The module {@code JitsiMeetJS} (which will be
+ * exported and may be attached to {@code window} by webpack later on).
+ * @private
+ * @returns {Object} - A {@code JitsiMeetJS} module which contains all existing
+ * value of the namespace {@code JitsiMeetJS} (if any).
+ */
+function _mergeNamespaceAndModule(module) {
+    return (
+        typeof window.JitsiMeetJS === 'object'
+            ? Object.assign({}, window.JitsiMeetJS, module)
+            : module);
+}
+
+module.exports = _mergeNamespaceAndModule(ljm);