Revert "[FEATURE] Check extension key before upload"

This reverts commit 899c2f58d89b29b8fa5d02799974634852be29fd.

Reverted, because uploading very old extensions with keys considered invalid now was not possible (tt_address, tt_news)

Change-Id: I8958bb33a087af4a0948f1700ba3be8f3c4050d8
See: https://forge.typo3.org/issues/60882
Reviewed-on: http://review.typo3.org/32080
Reviewed-by: Christian Zenker <typo3@xopn.de>
Tested-by: Christian Zenker <typo3@xopn.de>