QPID-6023: make the broker module depend on the 1.0 websocket plugin, thus adding it to the brokers binary release assembly.

The license and notice files for the broker assembly already have relevant Jetty entries, no change needed for the additional dependency.

merge from trunk r1619065


git-svn-id: https://svn.apache.org/repos/asf/qpid/branches/0.30@1619095 13f79535-47bb-0310-9956-ffa450edef68