Replaced writeData in design management

app/assets/javascripts/design_management/index.js

 import Vue from 'vue';
 import App from './components/app.vue';
 import apolloProvider from './graphql';
+import activeDiscussionQuery from './graphql/queries/active_discussion.query.graphql';
 import createRouter from './router';
 
 export default () => {
@@ -8,7 +9,8 @@ export default () => {
   const { issueIid, projectPath, issuePath } = el.dataset;
   const router = createRouter(issuePath);
 
-  apolloProvider.clients.defaultClient.cache.writeData({
+  apolloProvider.clients.defaultClient.cache.writeQuery({
+    query: activeDiscussionQuery,
     data: {
       activeDiscussion: {
         __typename: 'ActiveDiscussion',