Wait for requests when expanding diffs in feature spec

spec/features/merge_request/user_views_diffs_spec.rb

@@ -66,6 +66,7 @@
     expect(page).to have_button('Expand all')
 
     click_button 'Expand all'
+    wait_for_requests
 
     expect(page).not_to have_button('Expand all')
   end