[TASK] BE login template wrong

Accidentally reintroduced path to BE template.
Remove superfluous line again.

Releases: 6.2
Change-Id: I71dad6fbe2e8026999cff402c36b688a511cc4c6
Reviewed-on: https://review.typo3.org/20519
Reviewed-by: Markus Klein
Tested-by: Markus Klein