Update the vulnerable ActiveMQ client to the latest version

See https://github.com/PennState/jms-tools/network/alert/pom.xml/org.apache.activemq:activemq-client/open

The recommended solution is:

```
<dependency>
  <groupId>org.apache.activemq</groupId>
  <artifactId>activemq-client</artifactId>
  <version>[5.15.16,)</version>
</dependency>
```