use try-with-resource to mute warning about udpSocket not being closed

java/com.sap.sailing.expeditionconnector/src/com/sap/sailing/expeditionconnector/UDPMirror.java

@@ -30,7 +30,7 @@ public class UDPMirror {
             }
             int listeningOnPort = Integer.valueOf(args[c++]);
             byte[] buf = new byte[65536];
-            DatagramSocket udpSocket = new DatagramSocket(listeningOnPort);
+            try (DatagramSocket udpSocket = new DatagramSocket(listeningOnPort)) {
                 DatagramPacket received = new DatagramPacket(buf, buf.length);
                 DatagramSocket[] sendingSockets = new DatagramSocket[(args.length - 1) / 2];
                 DatagramPacket[] mirroredPackets = new DatagramPacket[(args.length - 1) / 2];
@@ -53,6 +53,7 @@ public class UDPMirror {
                 }
             }
         }
+    }
     
     private static void usage() {
         System.out.println("Usage: java "+UDPMirror.class.getName()+" [-v] <listeningport> hostname1 port1 [hostname2 port2]*");