Fixed Error: only one instance of babel-polyfill is allowed

app/features/conference/components/Conference.js

@@ -95,6 +95,10 @@ class Conference extends Component<Props, State> {
     constructor() {
         super();
 
+        // External API will load an instance of babel-polyfill. Hence we
+        // should remove existing babel-polyfill instance.
+        delete global._babelPolyfill;
+
         this.state = {
             isLoading: true
         };