Add missing command handler connection that I forgot about

node/src/client.js

@@ -770,6 +770,7 @@ export default class PeerClient {
 				send_chat: this.sendChat,
 				send_media: this.sendMedia,
 				delete_chat: this.deleteChat,
+				mark_read: this.markRead,
 			}[req.command] || this.handleUnknownCommand
 		}
 		const resp = { id: req.id }