[JENKINS-21984] Checking stable UC as well. Cannot reproduce certificate problem in test.
[JENKINS-21984] Disabling cert check on updateDirectlyWithJson since the certificate is now expired, and it is no good to have a test which is known to start failing at a particular time in the future!
Merge branch 'master' into DownloadSettings-JENKINS-19081

Conflicts:
	test/src/test/java/hudson/model/UpdateSiteTest.java