AbstractMethodError with barchart-udt

Motivation:

`SocketChannelUDT` from barchart-udt does not have the java 7 `public abstract SocketChannel bind(SocketAddress local)` method. Calling the abstract method `SocketChannel.bind(SocketAddress localAddress)` for `SocketChannelUDT` leads to an `AbstractMethodError` runtime error.

Modifications:

Make workaround with explicit call of `SocketChannelUDT.bind(SocketAddress local)` as it done in `NioUdtByteConnectorChannel`.

Result:

Fixes [netty#6934].

transport-udt/src/main/java/io/netty/channel/udt/nio/NioUdtMessageConnectorChannel.java

@@ -31,8 +31,12 @@
 import io.netty.util.internal.logging.InternalLogger;
 import io.netty.util.internal.logging.InternalLoggerFactory;
 
+import java.io.IOException;
 import java.net.InetSocketAddress;
 import java.net.SocketAddress;
+import java.security.AccessController;
+import java.security.PrivilegedActionException;
+import java.security.PrivilegedExceptionAction;
 import java.util.List;
 
 import static java.nio.channels.SelectionKey.*;
@@ -98,7 +102,7 @@ public UdtChannelConfig config() {
 
     @Override
     protected void doBind(final SocketAddress localAddress) throws Exception {
-        SocketUtils.bind(javaChannel(), localAddress);
+        privilegedBind(javaChannel(), localAddress);
     }
 
     @Override
@@ -233,4 +237,19 @@ public InetSocketAddress localAddress() {
     public InetSocketAddress remoteAddress() {
         return (InetSocketAddress) super.remoteAddress();
     }
+
+    private static void privilegedBind(final SocketChannelUDT socketChannel, final SocketAddress localAddress)
+            throws IOException {
+        try {
+            AccessController.doPrivileged(new PrivilegedExceptionAction<Void>() {
+                @Override
+                public Void run() throws IOException {
+                    socketChannel.bind(localAddress);
+                    return null;
+                }
+            });
+        } catch (PrivilegedActionException e) {
+            throw (IOException) e.getCause();
+        }
+    }
 }