Fixes Transport Client that start up with shield in the classpath

Now a NOOP transport filter is bound by to the secured transport service in a transport client

Fixes elastic/elasticsearch#165

Original commit: elastic/x-pack-elasticsearch@7268bd445c

src/main/java/org/elasticsearch/shield/transport/SecuredTransportModule.java

@@ -53,6 +53,7 @@ public class SecuredTransportModule extends AbstractShieldModule.Spawn implement
         if (clientMode) {
             // no ip filtering on the client
             bind(N2NNettyUpstreamHandler.class).toProvider(Providers.<N2NNettyUpstreamHandler>of(null));
+            bind(TransportFilter.class).toInstance(TransportFilter.NOOP);
             return;
         }
 

src/main/java/org/elasticsearch/shield/transport/TransportFilter.java

@@ -13,6 +13,8 @@ import org.elasticsearch.transport.TransportResponse;
  */
 public interface TransportFilter {
 
+    static final TransportFilter NOOP = new Base();
+
     /**
      * Called just before the given request is about to be sent. Any exception thrown
      * by this method will stop the request from being sent.