fix text scramble animation on registration

js/views/session_registration_view.js

@@ -120,7 +120,7 @@
   window.Session = window.Session || {};
 
   window.Session.setNewSessionID = sessionID => {
-    const el = document.querySelector('.session-id-editable');
+    const el = document.querySelector('.session-id-editable-textarea');
     const fx = new TextScramble(el);
     el.value = sessionID;
     fx.setText(sessionID);

ts/components/session/SessionIdEditable.tsx

@@ -30,6 +30,7 @@ export class SessionIdEditable extends React.PureComponent<Props> {
     return (
       <div className="session-id-editable">
         <textarea
+          className="session-id-editable-textarea"
           ref={this.inputRef}
           placeholder={placeholder}
           disabled={!editable}