failOnError parameter does not work as expected when the plugin execution fails at the authentication part. This happens if the whole RocketChat server is unreachable.

Stacktrace:

jenkins.plugins.rocketchatnotifier.rocket.errorhandling.RocketClientException: Please check if the server API https://xxx.com/api/v1/login is correct: (Login-Error 1)
at jenkins.plugins.rocketchatnotifier.rocket.RocketChatBasicCallAuthentication.doAuthentication(RocketChatBasicCallAuthentication.java:51)
at jenkins.plugins.rocketchatnotifier.rocket.RocketChatClientCallBuilder.buildCall(RocketChatClientCallBuilder.java:90)
at jenkins.plugins.rocketchatnotifier.rocket.RocketChatClientCallBuilder.buildCall(RocketChatClientCallBuilder.java:80)
at jenkins.plugins.rocketchatnotifier.rocket.RocketChatClientImpl.getChannels(RocketChatClientImpl.java:90)
at jenkins.plugins.rocketchatnotifier.RocketClientImpl.<init>(RocketClientImpl.java:30)
at jenkins.plugins.rocketchatnotifier.workflow.RocketSendStep$RocketSendStepExecution.getRocketClient(RocketSendStep.java:249)
at jenkins.plugins.rocketchatnotifier.workflow.RocketSendStep$RocketSendStepExecution.run(RocketSendStep.java:225)
at jenkins.plugins.rocketchatnotifier.workflow.RocketSendStep$RocketSendStepExecution.run(RocketSendStep.java:181)
at org.jenkinsci.plugins.workflow.steps.AbstractSynchronousNonBlockingStepExecution$1$1.call(AbstractSynchronousNonBlockingStepExecution.java:47)
at hudson.security.ACL.impersonate(ACL.java:290)
at org.jenkinsci.plugins.workflow.steps.AbstractSynchronousNonBlockingStepExecution$1.run(AbstractSynchronousNonBlockingStepExecution.java:44)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
Caused by: com.mashape.unirest.http.exceptions.UnirestException: java.lang.RuntimeException: java.lang.RuntimeException: org.json.JSONException: A JSONArray text must start with '[' at 1 [character 2 line 1]
at com.mashape.unirest.http.HttpClientHelper.request(HttpClientHelper.java:143)
at com.mashape.unirest.request.BaseRequest.asJson(BaseRequest.java:68)
at jenkins.plugins.rocketchatnotifier.rocket.RocketChatBasicCallAuthentication.doAuthentication(RocketChatBasicCallAuthentication.java:49)
... 15 more