Use JSON when POSTing data

src/controllers/wizard/user/index.js

@@ -23,10 +23,10 @@ function submit(form) {
     const apiClient = getApiClient();
     apiClient.ajax({
         type: 'POST',
-        data: {
+        data: JSON.stringify({
             Name: form.querySelector('#txtUsername').value,
             Password: form.querySelector('#txtManualPassword').value
-        },
+        }),
         url: apiClient.getUrl('Startup/User')
     }).then(onUpdateUserComplete);
 }