[BUGFIX] Resolves typo in system environment check

Changes 'freettype' to 'freetype'

Change-Id: I257cbe5fb084aa490fc73075911facd494e68346
Resolves: #47687
Releases: 6.2, 6.1
Reviewed-on: https://review.typo3.org/20291
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn