[BUGFIX] Undefined but existing controller action "accept"

Change-Id: I23c804fd805e6c71ff0d4c2445c3106de334cf40
Reviewed-on: https://review.typo3.org/31545
Reviewed-by: Sebastian Fischer <typo3@evoweb.de>
Tested-by: Sebastian Fischer <typo3@evoweb.de>