4905: add empty json for playlist slide get request

Author: sinejespersen

assets/tests/admin/admin-campaign.spec.js

@@ -5,7 +5,7 @@ import {
   beforeEachTest,
   loginTest,
 } from "./test-helper.js";
-import { slidesJson1 } from "./data-fixtures.js";
+import { emptyJson, slidesJson1 } from "./data-fixtures.js";
 
 test.describe("Campaign pages work", () => {
   test.beforeEach(async ({ page }) => {
@@ -35,6 +35,7 @@ test.describe("Campaign pages work", () => {
   test("It removes slide", async ({ page }) => {
     // Intercept slides in dropdown
     await fulfillDataRoute(page, "**/slides*", slidesJson1);
+    await fulfillDataRoute(page, "**/playlists/*/slides*", emptyJson);
 
     // Pick slide
     await page