[BUGFIX] Link to ext:perm in clickmenu not working

The link refers directly to index.php instead of mod.php.
Use BackendUtility::getModuleUrl() for the link to fix the problem.

Resolves: #62459
Related: #38099
Releases: master, 6.2, 6.1
Change-Id: I3b86d97a4f35a96ca39af28e724067b5ec8a832f
Reviewed-on: http://review.typo3.org/33510
Reviewed-by: Tymoteusz Motylewski <t.motylewski@gmail.com>
Tested-by: Tymoteusz Motylewski <t.motylewski@gmail.com>
Reviewed-by: Markus Klein <klein.t3@reelworx.at>
Tested-by: Markus Klein <klein.t3@reelworx.at>