upgradded jetty version

Author: rezra3

pom.xml

@@ -8,7 +8,7 @@
 	<properties>
 		<prometheus_client_version>0.7.0</prometheus_client_version>
 		<drop_wizard_version>3.2.6</drop_wizard_version>
-		<jetty_version>9.4.17.v20190418</jetty_version>
+		<jetty_version>9.4.21.v20190926</jetty_version>
 	</properties>
 	<build>
 		<sourceDirectory>src/external/mysql_lib</sourceDirectory>