[BUGFIX] Deprecated interface usage in scheduler task additional field providers

Change-Id: If3ae2b4d53cbde715289d644ef14ba428d7384e3
Reviewed-on: https://review.typo3.org/31597
Reviewed-by: Stefan Rotsch
Tested-by: Stefan Rotsch
Merge branch 'master' into TYPO3_6-2

* master:
  Added composer support
(Re-)Enabled checkbox "realurl" of tx_crawler_configuration