NullPointerException in ManagedDatagramSocketBinding.close

Issue

• We see a NullPointerException like the following upon start up:

Caused by: java.lang.NullPointerException
    at org.jboss.as.network.ManagedDatagramSocketBinding.close(ManagedDatagramSocketBinding.java:73)
    at java.net.DatagramSocket.<init>(DatagramSocket.java:245) [rt.jar:1.8.0_45]
    at org.jboss.as.network.ManagedDatagramSocketBinding.<init>(ManagedDatagramSocketBinding.java:41)
    at org.jboss.as.network.SocketBindingManagerImpl.createDatagramSocket(SocketBindingManagerImpl.java:77)
    at org.jboss.as.clustering.jgroups.ManagedSocketFactory.createDatagramSocket(ManagedSocketFactory.java:102)
    at org.jboss.as.clustering.jgroups.ManagedSocketFactory.createDatagramSocket(ManagedSocketFactory.java:112)
    at org.jgroups.protocols.UDP.createDatagramSocketWithBindPort(UDP.java:480)
    at org.jgroups.protocols.UDP.createSockets(UDP.java:328)
    at org.jgroups.protocols.UDP.start(UDP.java:225)