fix: incorrect signature for Channel#joinCall

src/classes/Channel.ts

@@ -802,7 +802,7 @@ export class Channel {
    * @param recipients Ring targets
    * @returns LiveKit URL and Token
    */
-  async joinCall(node = undefined, forceDisconnect = true, recipients: (User | string)[]) {
+  async joinCall(node?: string, forceDisconnect = true, recipients: (User | string)[] = []) {
     return await this.#collection.client.api.post(
       `/channels/${this.id as ''}/join_call`, {
       node,