Bump jetty.version in /its/it-tests

Bumps `jetty.version` from 9.3.11.v20160721 to 9.4.24.v20191120.

Updates `jetty-server` from 9.3.11.v20160721 to 9.4.24.v20191120
- [Release notes](https://github.com/eclipse/jetty.project/releases)
- [Commits](jetty/jetty.project@jetty-9.3.11.v20160721...jetty-9.4.24.v20191120)

Updates `jetty-servlet` from 9.3.11.v20160721 to 9.4.24.v20191120
- [Release notes](https://github.com/eclipse/jetty.project/releases)
- [Commits](jetty/jetty.project@jetty-9.3.11.v20160721...jetty-9.4.24.v20191120)

Updates `jetty-proxy` from 9.3.11.v20160721 to 9.4.24.v20191120
- [Release notes](https://github.com/eclipse/jetty.project/releases)
- [Commits](jetty/jetty.project@jetty-9.3.11.v20160721...jetty-9.4.24.v20191120)

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

its/it-tests/pom.xml

@@ -11,7 +11,7 @@
   <description>Integration tests</description>
 
   <properties>
-    <jetty.version>9.3.11.v20160721</jetty.version>
+    <jetty.version>9.4.24.v20191120</jetty.version>
     <logback.version>1.1.7</logback.version>
     <sonar.skip>true</sonar.skip>
     <skipTests>true</skipTests>