Bump guava from 28.0-jre to 29.0-jre in /vpn-admin

Bumps [guava](https://github.com/google/guava) from 28.0-jre to 29.0-jre.
- [Release notes](https://github.com/google/guava/releases)
- [Commits](https://github.com/google/guava/commits)

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

Author: dependabot[bot]

vpn-admin/pom.xml

@@ -104,7 +104,7 @@
         <dependency>
             <groupId>com.google.guava</groupId>
             <artifactId>guava</artifactId>
-            <version>28.0-jre</version>
+            <version>29.0-jre</version>
         </dependency>
         <!-- https://mvnrepository.com/artifact/com.h2database/h2 -->
         <dependency>