[BUGFIX] Responsive Images - Remove whitespaces in tags

Remove some unnecessary whitespaces in the html
tags that are genereted by the responsive image feature.

Resolves: #53220
Releases: 6.2
Change-Id: I49e73d92c74a1d3e656b0e847b22473cecf19a53
Reviewed-on: https://review.typo3.org/25067
Reviewed-by: Wouter Wolters
Tested-by: Wouter Wolters