message: Use async/await in allowed meta
diff: *
  * @example
  * const { ALLOWED_META } = require('@logux/server')
  - * function outMap (action, meta) {
  + * async function outMap (action, meta) {
  * const filtered = { }
  * for (const i in meta) {
  * if (ALLOWED_META.includes(i)) {
  * filtered[i] = meta[i]
  * }
  * }
  - * return Promise.resolve([action, filtered])
  + * return [action, filtered]
  * }
  */
  const ALLOWED_META = [
  