[BUGFIX] Avoid fatal error in scheduler

The scheduler object cleans up execution
arrays on instantiation. Due to the PSR-3
refactoring, the logger is instantiated
after the constructor is called - resulting
in a fatal error ("Call to member function info()
on null") when cleaning up the execution array.

The patch manually instantiates a logger if
there isn't one already.

Resolves: #85148
Releases: master
Change-Id: I5ff3a06a2b9d7e511d5d243df545359a48bf84b1
Reviewed-on: https://review.typo3.org/57118


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Reviewed-by: Joerg Boesche <typo3@joergboesche.de>
Reviewed-by: Daniel Gorges <daniel.gorges@b13.de>
Tested-by: Daniel Gorges <daniel.gorges@b13.de>
Reviewed-by: Steffen Frese <steffenf14@gmail.com>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Wouter Wolters <typo3@wouterwolters.nl>