[BUGFIX] Do not remove timezone offset from file dates on upload

When inserting database records during upload, there is no need
to remove the timezone offset from the date fields since we already
have UTC dates.

Change-Id: I072b5999183adf40af2e98a120fc3337d6df7d23
Resolves: #47868
Releases: 1.3
Reviewed-on: https://review.typo3.org/24899
Reviewed-by: Lorenz Ulrich
Tested-by: Lorenz Ulrich