HADOOP-14471. Upgrade Jetty to latest 9.3 version. Contributed by John Zhuge.

hadoop-project/pom.xml

@@ -35,7 +35,7 @@
 
     <failIfNoTests>false</failIfNoTests>
     <maven.test.redirectTestOutputToFile>true</maven.test.redirectTestOutputToFile>
-    <jetty.version>9.3.11.v20160721</jetty.version>
+    <jetty.version>9.3.19.v20170502</jetty.version>
     <test.exclude>_</test.exclude>
     <test.exclude.pattern>_</test.exclude.pattern>