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

Reviewed-by: cxorm <lianp964@gmail.com>
(cherry picked from commit 6040e86)
(cherry picked from commit 7f75355)

Author: jojochuang

hadoop-project/pom.xml

@@ -35,7 +35,7 @@
 
     <failIfNoTests>false</failIfNoTests>
     <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>