HADOOP-17625. Update to Jetty 9.4.39. (#2870)

Reviewed-by: cxorm <lianp964@gmail.com>
diff --git a/hadoop-project/pom.xml b/hadoop-project/pom.xml
index bb021fc..5f81d75 100644
--- a/hadoop-project/pom.xml
+++ b/hadoop-project/pom.xml
@@ -37,7 +37,7 @@
     <!--Whether to proceed to next module if any test failures exist-->
     <ignoreTestFailure>true</ignoreTestFailure>
     <maven.test.redirectTestOutputToFile>true</maven.test.redirectTestOutputToFile>
-    <jetty.version>9.4.35.v20201120</jetty.version>
+    <jetty.version>9.4.39.v20210325</jetty.version>
     <test.exclude>_</test.exclude>
     <test.exclude.pattern>_</test.exclude.pattern>