Revert "[#17027] if annual diff is empty, take from current annual"
Revert "[#17027] if annual diff is empty, take from current annual"

This reverts commit 6ea2e4b5a711367f9f404e61538798c0ccff1b58.

See https://projekte.systopia.de/issues/17027#note-18

systopia/de.systopia.contract,systopia/de.systopia.contract,systopia/de.systopia.contract