[BUGFIX] Complete Iframe-Progressbar in IE

Releases: master
Resolves: #66563
Change-Id: I23be4cab776252afff25f3f23c8fee2f4c09fad5
Reviewed-on: http://review.typo3.org/38887


Reviewed-by: Markus Klein <klein.t3@reelworx.at>
Tested-by: Markus Klein <klein.t3@reelworx.at>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Wouter Wolters <typo3@wouterwolters.nl>