Tests: Remove platform specific assertion in NioSocketChannelTests

This check depends on the language settings on the system the
test runs on, e.g. it fails on Ubuntu with LANG=de_DE.UTF-8.

Author: cbuescher

test/framework/src/test/java/org/elasticsearch/transport/nio/channel/NioSocketChannelTests.java

@@ -26,7 +26,6 @@
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.locks.LockSupport;
 
-import static org.hamcrest.Matchers.containsString;
 import static org.hamcrest.Matchers.instanceOf;
 
 public class NioSocketChannelTests extends AbstractNioChannelTestCase {
@@ -68,7 +67,6 @@ public void testConnectFails() throws IOException, InterruptedException {
         assertTrue(socketChannel.isOpen());
         assertTrue(connectFuture.connectFailed());
         assertThat(connectFuture.getException(), instanceOf(ConnectException.class));
-        assertThat(connectFuture.getException().getMessage(), containsString("Connection refused"));
 
         thread.join();
     }