Bump cas-server-webapp-tomcat from 5.3.2 to 5.3.16 in /examples

Bumps [cas-server-webapp-tomcat](https://github.com/apereo/cas) from 5.3.2 to 5.3.16.
- [Release notes](https://github.com/apereo/cas/releases)
- [Commits](apereo/cas@v5.3.2...v5.3.16)

---
updated-dependencies:
- dependency-name: org.apereo.cas:cas-server-webapp-tomcat
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

examples/war/overlay/build.gradle

@@ -3,7 +3,7 @@ apply plugin: "io.freefair.war-overlay"
 war {
  overlays {
  cas {
- from "org.apereo.cas:cas-server-webapp-tomcat:5.3.2@war"
+ from "org.apereo.cas:cas-server-webapp-tomcat:5.3.16@war"
  }
  }
 }