REVIEW: only wait for Jetty server component if it has started without exception

This is a cleaner version of #680 that is more clear in its intention. Previously we would always attempt to wait for the Jetty server component even if it threw an exception when starting. Now we only join the Jetty server component when it starts without exception.

http://bamboo.s/browse/NX-OSSF216-1 :white_check_mark: