[BUGFIX] Deactivate output buffer for FileDumpEID.php

If you try to download large file via FileDumpEID.php you may
get an out of memory error.

Resolves: #64273
Releases: master, 6.2
Change-Id: Ie1fcf9eac5d8e7466bbfe6eb8357ed9ce62fa649
Reviewed-on: http://review.typo3.org/36485


Reviewed-by: Philipp Gampe <philipp.gampe@typo3.org>
Tested-by: Philipp Gampe <philipp.gampe@typo3.org>
Reviewed-by: Sebastian Fischer <typo3@evoweb.de>
Tested-by: Sebastian Fischer <typo3@evoweb.de>
Reviewed-by: Ingo Schmitt <is@marketing-factory.de>
Tested-by: Ingo Schmitt <is@marketing-factory.de>