fix(qBittorrent): Add torrent files without authentication (#768)

authCookie resolves to undefined when used without authentication. This lead to axios throwing ERR_HTTP_INVALID_HEADER_VALUE. Fixed to use the same method getRequestHeaders instead of the direct this.authCookie call, so it does not try to send the request with Cookie: undefined header.

server/services/qBittorrent/clientRequestManager.ts

@@ -422,7 +422,7 @@ class ClientRequestManager {
     });
 
     const headers = form.getHeaders({
-      Cookie: await this.authCookie,
+      ...(await this.getRequestHeaders()),
       'Content-Length': form.getLengthSync(),
     });