NullPointerException in TxConnectionManager$TxConnectionEventListener.connectionClosed

Issue

• We see the following NPE when trying to close a connection during server shutdown:

INFO  [org.jboss.resource.connectionmanager.TxConnectionManager] throwable from unregister connection 
java.lang.NullPointerException 
        at org.jboss.resource.connectionmanager.TxConnectionManager$TxConnectionEventListener.connectionClosed(TxConnectionManager.java:797) 
        at org.jboss.resource.adapter.jdbc.BaseWrapperManagedConnection.closeHandle(BaseWrapperManagedConnection.java:363) 
        at org.jboss.resource.adapter.jdbc.WrappedConnection.close(WrappedConnection.java:156)