[energidataservice] Fix IllegalStateException

[jlaur]

Deeper testing unfortunately revealed a regression from previous refactoring - after restarting binding:

2023-10-02 21:09:05.424 [WARN ] [mmon.WrappedScheduledExecutorService] - Scheduled runnable ended with an exception: 
java.lang.IllegalStateException: Datahub records not initialized
	at org.openhab.binding.energidataservice.internal.CacheManager.areTariffsValidTomorrow(CacheManager.java:251) ~[?:?]
	at org.openhab.binding.energidataservice.internal.handler.EnergiDataServiceHandler.downloadTariffs(EnergiDataServiceHandler.java:241) ~[?:?]
	at org.openhab.binding.energidataservice.internal.handler.EnergiDataServiceHandler.refreshElectricityPrices(EnergiDataServiceHandler.java:177) ~[?:?]
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:539) ~[?:?]
	at java.util.concurrent.FutureTask.run(FutureTask.java:264) ~[?:?]
	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:304) ~[?:?]
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136) [?:?]
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635) [?:?]
	at java.lang.Thread.run(Thread.java:833) [?:?]

Regression of #15651

[jlaur]

@wborn - sorry for this follow-up to #15651. Do you think you can review this as well? It will fix snapshot versions as well as minimize my effort on other active development and backports for production testing. 🙂

[wborn]

Thanks for the fix!

[jlaur]

@wborn - thanks!