Make sure Hochwasserberichte from Hochwasserzentrale Sachsen-Anhalt actually work
As discussed in !290 (comment 36492) we could not test the Hochwasserberichte actually working becuase at the time of writing the scraper none we currently available (including the archived ones). We still added the implementation in best effort manner, but as some reports are available we should make sure that it actually works.