[BUGFIX] Check for exceptions instead of number of affected rows

Saving a scheduler task without any changes leads to 0 affected
rows which must not be interpreted as an error.

Resolves: #85366
Releases: master, 8.7
Change-Id: I474e16478cb09ad4940aaab5fe1d3eb21498c4c4
Reviewed-on: https://review.typo3.org/57358


Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Frans Saris <franssaris@gmail.com>
Reviewed-by: Stefan Neufeind <typo3.neufeind@speedpartner.de>
Tested-by: Stefan Neufeind <typo3.neufeind@speedpartner.de>
Reviewed-by: Rudy Gnodde <rgn@windinternet.nl>
Tested-by: Rudy Gnodde <rgn@windinternet.nl>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>