The JettySockJsIntegrationTests are enabled in the performance build
only. Following the upgrade to Jetty 9.3 where the
JettyRequestUpgradeStrategy is now Lifecycle as wel as
ServletContextAware, we need to make sure the ApplicationContext
refresh occurs after the ServletContext has been set. This change
removes the explicit .refresh() call in the test setup and instead
relies on the DispatcherServlet to do that, which ensures that the
ServletContext with which it is initialized by Jetty has been set
on the ApplicationContext before that.
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