[BUGFIX] Don't underline Web>Page content elements on hover

Resolves: #53683
Releases: 6.2
Change-Id: I71af8c928e0a83698e887e9053d1c6de1e8d8ffb
Reviewed-on: https://review.typo3.org/25464
Reviewed-by: Felix Kopp
Tested-by: Felix Kopp
Reviewed-by: Georg Ringer
Tested-by: Georg Ringer