Events first one and last one are always the same

[zsarosi]

In the issue, the text "Events:" prints always the same value for the first and last one. E.g.: "Events: Got 2 events, the first one vor 31m 48s and the last one vor 31m 48s."
I also checked the DB, and the values of ts_first_event and ts_last_modified are the same since 2023-07-10, before that day we have issues where the two timestamps are different. We made an update of the module on that day (either Thomas-Gelf-icingaweb2-module-eventtracker-v0.9.0-306-g02dcd61.tar.gz or Thomas-Gelf-icingaweb2-module-eventtracker-v0.9.0-307-g401eae1.tar.gz), since then are the two timestamps identical.