UDPBroadcastThreadTest was often failing on ci.jenkins-ci.org; making more lenient.

Mar 4, 2013 10:55:46 PM hudson.UDPBroadcastThread run
WARNING: UDP handling problem
java.io.IOException: Operation not permitted
	at java.net.PlainDatagramSocketImpl.send(Native Method)
	at java.net.DatagramSocket.send(DatagramSocket.java:625)
	at hudson.UDPBroadcastThread.run(UDPBroadcastThread.java:98)
→
java.net.SocketTimeoutException: Receive timed out
	at java.net.PlainDatagramSocketImpl.receive0(Native Method)
	at java.net.PlainDatagramSocketImpl.receive(PlainDatagramSocketImpl.java:145)
	at java.net.DatagramSocket.receive(DatagramSocket.java:725)
	at hudson.UDPBroadcastThreadTest.receiveAndVerify(UDPBroadcastThreadTest.java:70)
	at hudson.UDPBroadcastThreadTest.testMulticast(UDPBroadcastThreadTest.java:51)