[BUGFIX] Refresh iconElement after its content has been replaced

[BUGFIX] Refresh iconElement after its content has been replaced

The variable iconElement refers now correctly to the original jQuery
object and is really reverted to the old class as the comment implies.

Resolves: #82624
Releases: master, 8.7
Change-Id: I13615bbee6d5148fe940bac49b72c2766c0a1de7
Reviewed-on: https://review.typo3.org/53258
Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Joerg Boesche <typo3@joergboesche.de>
Reviewed-by: Andreas Fernandez <typo3@scripting-base.de>
Tested-by: Andreas Fernandez <typo3@scripting-base.de>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>