Bump jetty.version in /environments/servlet

Bumps `jetty.version` from 9.4.14.v20181114 to 9.4.25.v20191220.

Updates `jetty-server` from 9.4.14.v20181114 to 9.4.25.v20191220
- [Release notes](https://github.com/eclipse/jetty.project/releases)
- [Commits](jetty/jetty.project@jetty-9.4.14.v20181114...jetty-9.4.25.v20191220)

Updates `jetty-servlet` from 9.4.14.v20181114 to 9.4.25.v20191220
- [Release notes](https://github.com/eclipse/jetty.project/releases)
- [Commits](jetty/jetty.project@jetty-9.4.14.v20181114...jetty-9.4.25.v20191220)

Updates `jetty-plus` from 9.4.14.v20181114 to 9.4.25.v20191220
- [Release notes](https://github.com/eclipse/jetty.project/releases)
- [Commits](jetty/jetty.project@jetty-9.4.14.v20181114...jetty-9.4.25.v20191220)

Updates `jetty-jndi` from 9.4.14.v20181114 to 9.4.25.v20191220
- [Release notes](https://github.com/eclipse/jetty.project/releases)
- [Commits](jetty/jetty.project@jetty-9.4.14.v20181114...jetty-9.4.25.v20191220)

Updates `jetty-webapp` from 9.4.14.v20181114 to 9.4.25.v20191220
- [Release notes](https://github.com/eclipse/jetty.project/releases)
- [Commits](jetty/jetty.project@jetty-9.4.14.v20181114...jetty-9.4.25.v20191220)

Updates `jetty-annotations` from 9.4.14.v20181114 to 9.4.25.v20191220
- [Release notes](https://github.com/eclipse/jetty.project/releases)
- [Commits](jetty/jetty.project@jetty-9.4.14.v20181114...jetty-9.4.25.v20191220)

Updates `jetty-util` from 9.4.14.v20181114 to 9.4.25.v20191220
- [Release notes](https://github.com/eclipse/jetty.project/releases)
- [Commits](jetty/jetty.project@jetty-9.4.14.v20181114...jetty-9.4.25.v20191220)

Updates `jetty-deploy` from 9.4.14.v20181114 to 9.4.25.v20191220
- [Release notes](https://github.com/eclipse/jetty.project/releases)
- [Commits](jetty/jetty.project@jetty-9.4.14.v20181114...jetty-9.4.25.v20191220)

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

environments/servlet/pom.xml

@@ -28,7 +28,7 @@
     <properties>
         <jsf.version>2.3.2</jsf.version>
         <tomcat.version>9.0.30</tomcat.version>
-        <jetty.version>9.4.14.v20181114</jetty.version>
+        <jetty.version>9.4.25.v20191220</jetty.version>
         <jetty9.asm.version>7.0</jetty9.asm.version>
         <!-- Jetty 6 API is used for GWT support only -->
         <jetty6.version>6.1.26</jetty6.version>