Fix reply indicator displaying wrong avatar in rare cases (#35756)

app/javascript/mastodon/features/compose/components/reply_indicator.jsx

@@ -25,7 +25,7 @@ export const ReplyIndicator = () => {
       <div className='reply-indicator__line' />
 
       <Link to={`/@${account.get('acct')}`} className='detailed-status__display-avatar'>
-        <Avatar account={account} size={46} />
+        <Avatar key={`avatar-${account.get('id')}`} account={account} size={46} />
       </Link>
 
       <div className='reply-indicator__main'>