Add new errorCode 4 of NarrowcastProgressResponse (#1120)

A new errorCode has been added to NarrowcastProgressResponse.
New number is 4. 4 means an audience of less than 50 recipients is
included as a condition of sending.

Previously, it was not possible to determine whether an error occurred
due to a lack of enough recipients or because an audience of less than
50 recipients is included as a condition of sending. This will be fixed
with the update to the Messaging API, so the description of errorCode on
OpenAPI will also be revised.

Co-authored-by: github-actions <github-actions@github.com>

lib/messaging-api/model/narrowcastProgressResponse.ts

@@ -42,7 +42,7 @@ export type NarrowcastProgressResponse = {
    */
   failedDescription?: string /**/;
   /**
-   * Error summary. This is only included with a phase property value of failed. One of:  `1`: An internal error occurred. `2`: An error occurred because there weren\'t enough recipients. `3`: A conflict error of requests occurs because a request that has already been accepted is retried.
+   * Error summary. This is only included with a phase property value of failed. One of:  `1`: An internal error occurred. `2`: An error occurred because there weren\'t enough recipients. `3`: A conflict error of requests occurs because a request that has already been accepted is retried. `4`: An audience of less than 50 recipients is included as a condition of sending.
    *
    * @see <a href="https://developers.line.biz/en/reference/messaging-api/#get-narrowcast-progress-status">errorCode Documentation</a>
    */