ConsumeSlack throwing NullPointerException for latestReply field

I have an instance of ConsumeSlack that is throwing NullPointerExceptions:
```

2024-02-22 21:33:08,239 ERROR [Timer-Driven Process Thread-6] o.a.nifi.processors.slack.ConsumeSlack ConsumeSlack[id=55d6ad46-018d-1000-0000-000024aa6dbf] Failed to retrieve messages
java.lang.NullPointerException: Cannot invoke "String.split(String)" because "value" is null
    at org.apache.nifi.processors.slack.consume.SlackTimestamp.<init>(SlackTimestamp.java:42)
    at org.apache.nifi.processors.slack.consume.ConsumeChannel.fetchReplies(ConsumeChannel.java:637)
    at org.apache.nifi.processors.slack.consume.ConsumeChannel.consumeMessages(ConsumeChannel.java:493)
    at org.apache.nifi.processors.slack.consume.ConsumeChannel.consumeReplies(ConsumeChannel.java:268)
    at org.apache.nifi.processors.slack.consume.ConsumeChannel.consume(ConsumeChannel.java:173)
    at org.apache.nifi.processors.slack.ConsumeSlack.onTrigger(ConsumeSlack.java:346)
    at org.apache.nifi.processor.AbstractProcessor.onTrigger(AbstractProcessor.java:27)
    at org.apache.nifi.controller.StandardProcessorNode.onTrigger(StandardProcessorNode.java:1274)
    at org.apache.nifi.controller.tasks.ConnectableTask.invoke(ConnectableTask.java:244)
    at org.apache.nifi.controller.scheduling.TimerDrivenSchedulingAgent$1.run(TimerDrivenSchedulingAgent.java:102)
    at org.apache.nifi.engine.FlowEngine$2.run(FlowEngine.java:110)
    at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
    at java.base/java.util.concurrent.FutureTask.runAndReset(Unknown Source)
    at java.base/java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(Unknown Source)
    at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.base/java.lang.Thread.run(Unknown Source)

```