⬆️ Bump jetty.version from 9.4.28.v20200408 to 9.4.31.v20200723 (#1701)

Bumps `jetty.version` from 9.4.28.v20200408 to 9.4.31.v20200723.

Updates `jetty-server` from 9.4.28.v20200408 to 9.4.31.v20200723
- [Release notes](https://github.com/eclipse/jetty.project/releases)
- [Commits](jetty/jetty.project@jetty-9.4.28.v20200408...jetty-9.4.31.v20200723)

Updates `jetty-servlet` from 9.4.28.v20200408 to 9.4.31.v20200723
- [Release notes](https://github.com/eclipse/jetty.project/releases)
- [Commits](jetty/jetty.project@jetty-9.4.28.v20200408...jetty-9.4.31.v20200723)

Signed-off-by: dependabot[bot] <[email protected]>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

pom.xml

@@ -116,7 +116,7 @@
 
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     <httpclient.version>4.5</httpclient.version>
-    <jetty.version>9.4.28.v20200408</jetty.version>
+    <jetty.version>9.4.31.v20200723</jetty.version>
   </properties>
 
   <dependencyManagement>