fix migrations

Fix #8363

packages/backend/migration/1596786425167-channel2.js

@@ -1,6 +1,6 @@
-"use strict";
-Object.defineProperty(exports, "__esModule", { value: true });
-class channel21596786425167 {
+
+
+export class channel21596786425167 {
     constructor() {
         this.name = 'channel21596786425167';
     }
@@ -11,4 +11,3 @@ class channel21596786425167 {
         await queryRunner.query(`ALTER TABLE "channel_following" DROP COLUMN "readCursor"`);
     }
 }
-exports.channel21596786425167 = channel21596786425167;