[BUGFIX] Assign elementClassAttribute to ImageUpload element

Resolves: #84179
Releases: master, 8.7
Change-Id: I061674ab878dbfbd2483c17e46a48e2f606ddd87
Reviewed-on: https://review.typo3.org/56061
Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Susanne Moog <susanne.moog@typo3.org>
Tested-by: Susanne Moog <susanne.moog@typo3.org>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Tested-by: Andreas Fernandez <a.fernandez@scripting-base.de>

typo3/sysext/form/Resources/Private/Frontend/Partials/ImageUpload.html

@@ -5,6 +5,7 @@
 			property="{element.identifier}"
 			as="image"
 			id="{element.uniqueIdentifier}"
+			class="{element.properties.elementClassAttribute}"
 			errorClass="{element.properties.elementErrorClassAttribute}"
 			additionalAttributes="{formvh:translateElementProperty(element: element, property: 'fluidAdditionalAttributes')}"
 			accept="{element.properties.allowedMimeTypes}"