[BUGFIX] Recordlist: Removed call to deprecated method render()

Call of FlashMessage->render() if no records are on the page
was replaced with appropriate code.

Resolves: #73421
Releases: master, 7.6
Change-Id: If10a5a0ec4f71df6008369c83a9ab6a56c812d4e
Reviewed-on: https://review.typo3.org/46637


Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Wouter Wolters <typo3@wouterwolters.nl>
Reviewed-by: Frank Naegler <frank.naegler@typo3.org>
Tested-by: Frank Naegler <frank.naegler@typo3.org>