When I run a pipeline job using the `rocketSend` step (being in a `post` section), the job never ends.

In the Jenkins logs, I can see the following logs:

```
java.lang.ClassNotFoundException: org.apache.commons.lang.StringUtils
at java.base/java.net.URLClassLoader.findClass(URLClassLoader.java:377)
at jenkins.util.URLClassLoader2.findClass(URLClassLoader2.java:70)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:557)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:490)
Caused: java.lang.NoClassDefFoundError: org/apache/commons/lang/StringUtils
at PluginClassLoader for rocketchatnotifier//jenkins.plugins.rocketchatnotifier.RocketChatNotifier$DescriptorImpl.doCheckWebhookToken(RocketChatNotifier.java:667)
at java.base/java.lang.invoke.MethodHandle.invokeWithArguments(MethodHandle.java:735)
at org.kohsuke.stapler.Function$MethodFunction.invoke(Function.java:469)
```

The expected behaviour is sending the message to RocktChat successfully and no exception in the Jenkins logs.