Backport stub_default_url_options from EE

Used in https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/5782

spec/support/helpers/stub_configuration.rb

@@ -27,6 +27,11 @@ module StubConfiguration
     allow(Gitlab.config.gitlab).to receive_messages(to_settings(messages))
   end
 
+  def stub_default_url_options(host: "localhost", protocol: "http")
+    url_options = { host: host, protocol: protocol }
+    allow(Rails.application.routes).to receive(:default_url_options).and_return(url_options)
+  end
+
   def stub_gravatar_setting(messages)
     allow(Gitlab.config.gravatar).to receive_messages(to_settings(messages))
   end