fix branch-4.16 ci

Author: hangc0276

bookkeeper-server/src/test/java/org/apache/bookkeeper/proto/ClientSocketDisconnectTest.java

@@ -38,7 +38,7 @@
 import org.apache.bookkeeper.tls.SecurityException;
 import org.apache.bookkeeper.util.EventLoopUtil;
 import org.junit.Assert;
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
 @Slf4j
 public class ClientSocketDisconnectTest extends BookKeeperClusterTestCase {